Is there a very stinky chemical solution that isn't a health hazard?

An effective way to disperse rioters & looters would be to send an armored vehicle in to spray them with a very stinky liquid. Is there a chemical that stinks but is not a health risk and that breaks down after a few hours, or could be neutralized with another solution after a few hours? 




My vote would be for [butyric acid](http://en.wikipedia.org/wiki/Butyric_acid) and related short-chain fatty acids with between 3 and ~8 carbons (isobutyric acid, valeric acid, isovaleric acid, caproic acid, etc.)


In pure form these chemicals would be dangerous acids, but in dilute aqueous solution buffered at pH 5 or so, they are not very corrosive or toxic but are still pretty stinky.


Skatole could be another example. See the Wikipedia article for [malodorants](http://en.wikipedia.org/wiki/Malodorant) for some more ideas.


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Already done: See, for example, [Skunk](https://en.wikipedia.org/wiki/Skunk_(weapon)) which has been widely used by the Israeli Defense Forces.


Per its [manufacturer](http://www.skunk-skunk.com/), Skunk is:



> 
> A non-lethal ... deterrent [that] consists of an extremely
>  foul-smelling liquid, with the viscosity of water, that can be sprayed
>  over a large area using a standard water cannon.
> 
> 
> The Skunk is not volatile, it's inflammable – in fact, it can
>  even be used to put out fires in a pinch – and it poses no
>  health hazard. In fact, despite its outrageous smell, the Skunk liquid
>  is perfectly safe to consume.
> 
> 
> 


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