Who Me? was a top secret sulfurous stench weapon developed by the American Office of Strategic Services during World War II to be used by the French Resistance against German officers. Who Me? smelled strongly of fecal matter, and was issued in pocket atomizers intended to be unobtrusively sprayed on a German officer, humiliating him and, by extension, demoralizing the occupying German forces.

The experiment was very short-lived, however. Who Me? had a high concentration of extremely volatile sulfur compounds that were very difficult to control: more often than not the person who did the spraying ended up smelling as bad as the sprayee. After only two weeks it was concluded that Who Me? was a dismal failure. It remains unclear whether there was a successful Who Me? attack.

Who Me? was listed by the The Guinness Book of World Records as one of the two smelliest substances, the other being “US Government Standard Bathroom Malodor”, used to test deodorants and air fresheners[1]. Pam Dalton, a cognitive psychologist at the Monell Chemical Senses Center in Philadelphia, describes the smell of Who Me? as resembling “the worst garbage dumpster left in the street for a long time in the middle of the hottest summer ever”.

A recipe for a kilogram of the same or equivalent substance in circulation on the Internet specifies 919 g of white mineral oil as an inert carrier, and 20 g of skatole, 20 g of n-butanoic acid, 20 g of n-pentanoic acid, 20 g of n-hexanoic acid and 1 g of pentanethiol as the active ingredients.

for good measure:
Alinsky’s Rules of Tactics:

1 ) Power is not only what you have but what the enemy thinks you have.

2 ) Never go outside the experience of your people. It may result in confusion, fear and retreat.

3 ) Wherever possible go outside the experience of the enemy. Here you want to cause confusion, fear and retreat.

4 ) Make the enemy live up to his/her own book of rules.

5 ) Ridicule is man’s most potent weapon.

6 ) A good tactic is one that your people enjoy.

7 ) A tactic that drags on too long becomes a drag.

8 ) Keep the pressure on, with different tactics and actions and utilize all events of the period for your purpose.

9 ) The threat is usually more terrifying than the thing itself.

10 ) The major premise for tactics is the development of operations that will maintain a constant pressure upon the opposition.

11 ) If you push a negative hard and deep enough it will break through into its counterside.

12 ) The price of a successful attack is a constructive alternative.
13 ) Pick the target, freeze it, personalize it and polarize it.

A stink bomb or stinkbomb is a device designed to create an unpleasant smell. They range in effectiveness from simple pranks to military grade chemical agents.

At one end of the spectrum, relatively harmless stink bombs consist of ammonium sulfide, which smells strongly of rotten eggs. When exposed to air, the ammonium sulfide reacts with moisture, hydrolyzes, and a mixture of hydrogen sulphide and ammonia is released. Other popular substances on which to base stink bombs are thiols with lower molecular weight, e.g., methyl mercaptan and ethyl mercaptan — the chemicals that give odor to skunks and are added to natural gas. A variation on this idea is the scent bomb, or perfume bomb, filled with an overpowering “cheap perfume” smell. Prank stink bombs and perfume bombs are usually sold as a 1- or 2- ml sealed glass ampoule, which can be broken by throwing against a hard surface or by crushing under one’s shoe sole, thus releasing the odorous liquid contained therein. Another variety of prank stink bomb comprises two bags, one smaller and inside the other. The inner one contains a liquid and the outer one a powder. When the inner one is popped by squeezing it, the liquid reacts with the powder, producing hydrogen sulfide, which expands and pops the outer bag, releasing the putridity.

At the other end of the spectrum, the governments of Israel and the United States of America are developing stink bombs for use by their law enforcement agencies and militaries as riot control and area denial weapons. Using stink bombs for these purposes have advantages over traditional riot control agents: unlike pepper spray and tear gas, stink bombs are believed not to be dangerous, and they are effective at low concentrations.

The most effective stink bombs are those that contain a mixture of several stenches of biological origins. The biological odors used – vomit, human waste, body odors, burnt hair, and rotting garbage – are found universally revolting by people of all cultures. A mixture of various odors is more effective over time than a single odor, because it is much easier to acclimate to individual smells; a mixture therefore lasts longer and offers a greater impact.

The Guinness Book of Records [1] lists two smelliest substances. One is the “US Government Standard Bathroom Malodor”, a vile mixture of eight chemicals with stench resembling human feces, only much stronger, designed to test the efficacy of deodorizers and air fresheners. Another one, “Who me?”, is a mixture of five sulfur-containing chemicals and smells like rotting food and carcasses. “Who-me?” was designed during World War II, for use by the French Resistance to humiliate the German soldiers. Dalton of Monell has combined the worst of the two to make “Stench Soup”[2].

[edit] Chemicals used

Typically, lower molecular weight volatile organic compounds are used. Generally the higher molecular weight for a given class of compounds, the lower volatility and initial concentration but the longer persistence. It should be noted that some chemicals (typically thiols) have a certain concentration threshold over which the smell is not perceived significantly stronger; therefore a lower-volatility compound is capable of providing comparable stench intensity to a higher-volatility compound, but for longer time. Another issue is the operating temperature, on which the compound’s volatility strongly depends. Care should be taken as some compounds tend to be toxic in higher concentrations.

The most often encountered compounds are:

* Thiols
o Methanethiol (used rarely, it is a gas and therefore more difficult to handle than liquids)
o Ethanethiol deer urine
o Propanethiol
o Butanethiol, Eau de skunk
o Pentanethiol
* Other sulfur compounds
o Hydrogen sulfide, smelling of rotten eggs
* Carboxylic acids
o Propanoic acid, smelling like sweat
o Butanoic acid, strong foul smell, effective and long-lasting
o Pentanoic acid
o Hexanoic acid, smelling of cheese
* Aldehydes
* Amines
o Ethylamine, fishy smell
o Putrescine, smelling of rotten meat
o Cadaverine, smelling of rotten meat
* Heterocyclic compounds
o Indole
o Skatole, smelling of faeces

According to the 2000 edition of the Guinness Book Of World Records, ethanethiol is the “smelliest substance” in existence. Other more specialized chemicals were probably not examined, however. Most volatile thiols are comparably offensive. Thiols can be oxidized, and thus de-odourized, using bleach or related oxidants.

http://en.wikipedia.org/wiki/Butanethiol
Butanethiol, also known as butyl mercaptan, is a highly volatile, clear to yellowish liquid with a foetid (extremely foul-smelling) odor, commonly described as “skunk” odor. In fact, butanethiol is one of the major constituents of a skunk’s defensive spray. The scent of butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. Butanethiol is chemically classified among the thiols, which are organic compounds with molecular formulas and structural formulas similar to alcohols, except that sulfur-containing sulfhydryl group (-SH) replaces the oxygen-containing hydroxyl group in the molecule. Butanethiol’s basic molecular formula is C4H9SH, and its structural formula is similar to that of the alcohol butanol. Butanethiol is a thiol of low molecular weight, and it is highly flammable. Butanethiol is used as an industrial solvent, as an odorant for natural gas (which is odorless), and as an intermediate for insecticides and herbicides. It is sometimes placed in the “stink bombs” and “stink perfumes” that pranksters love to use.

Butanethiol is a very noxious and caustic chemical compound, and at sufficiently high concentrations, it produces serious health effects in both humans and animals, especially as a result of prolonged exposure. Sufficiently high concentrations of the foetid, volatile substance causes eye irritation, headaches, nausea and vomiting, dizziness, and irritation of the respiratory tract. Even higher concentrations can lead to unconsciousness and coma after prolonged exposure. Contact with the skin and mucous membranes causes burns, and contact with the eyes can lead to blurred vision or complete blindness.

Wikipedia also has a brief article on putrescine.

Not that either of these will help much unless one already has some background in college level organic chemistry – but they are interesting.

On a TOOOOTALLY different note, there is a concept we used in Special Forces when training “irregulars” It’s called a “confidence target.” Never send newly trained irregulars on a first mission that does not have a very high probability of success. Failure the first time out is disastrous and demoralizes a freshly recruited and freshly trained force. Simple, straightforward targets are always best so there is a gain of experience, but a gain of confidence at the same time.

Sorry to have digressed so.

One of the advanced chem classes in high school was trying to make some sort of artificial flavoring (raspberry, iirc) and they spilled butyric acid all over the place. Good lord, that was one of the most awful smells… like really Very Portly Men drunk on tequila barfing in a jacuzzi in a well-insulated room. And it spills over.

Also, all anaerobic decomposition creates butyric acid.

I’m getting carried away. Why don’t we load up on cabbage and bratwurst and pay an “official” visit to these conventions? (sorry, sorry)