Ideas from The O.S.S. during World war II. Funny history and is probably still being tested.
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 also ended up smelling as bad as the one targeted. After only two weeks it was concluded that Who Me was a dismal failure.
https://en.wikipedia.org/wiki/Who_MeStench warfare
By Stephanie Pain
GOTTA get out of here. Heart’s pounding. Can’t think. Can’t speak. Daren’t
breathe. Just run. As the stench rolls down the street, panic spreads.
Everyone’s on the run now. They don’t know what the evil-smelling odour is but
their noses tell them it’s dangerous, and within seconds their stomachs sound
the general alarm. In two minutes the streets are empty. All that’s left is a
terrible stink.
This hasn’t happened yet, but it could if the US Army succeeds in its effort
to create the mother of all stink bombs. Their aim is to have a weapon that
doesn’t kill or injure anyone, but instead triggers fear, panic and an
overwhelming urge to run away. The mixture of malodorous molecules has to add up
to a pong so repulsive it’s truly terrifying.
The search for the perfect stink bomb is part of the Pentagon’s Nonlethal
Weapons Program. The US Army wants a stink to drive away enemy troops or hostile
crowds and to enforce no-go zones around sensitive military installations. It
could also help peacekeeping forces keep warring factions apart by creating
stench-filled exclusion zones. Police forces would have plenty of uses for a
stink bomb, too. It would be ideal for ending a siege without firing a shot, or
for dispersing rioters or even marking the ringleaders so they can’t escape into
the crowd.
“It would give us an offensive capability against large and unruly groups of
people, if they are unwilling to move or are openly hostile,” says Pentagon
spokesman Lieutenant Colonel George Rhynedance. “And it would minimise the risk
to our own people and to the antagonists.”
https://www.newscientist.com/article/mg17122984.600-stench-warfare