I’m thinking they’re called ‘pepper balls’. (How ironic Is that?) As I recall, pepper balls are solid and pulverize into dust on impact, something of a long distance pepper spray.
Pepperball gun demonstration (and, yes, it creates a dust cloud just like we saw on the video of the idiot who tossed the tear gas canister back at police)
https://www.youtube.com/watch?v=qhoWk9L4-Eg