Over a decade ago, I read there was research on slippery foams that could be sprayed on a crowd or individual. There could still be injuries from falling, etc. But the sprayed would then find it difficult to hold anything or get back up.
Not saying this is the way to go, just wanted to point out an interesting tidbit.
I found this with a web search just now: https://www.military.com/defensetech/2003/04/15/slippery-sol...