There's great photos out there of a Hong Konger using a tennis or badminton racket to hit it back. I don't believe the foam would work because the burning bit

There's great photos out there of a Hong Konger using a tennis or badminton racket to hit it back. I don't believe the foam would work because the burning bit has its own oxidizer. I've seen fire extinguishers used to create a smokescreen and to make floors slippery, but water is enough for the tear gas cartridges (and people here really seem to prefer to throw them back).