Has anyone ever asked a teacher to implement a token rewards system with their kids?

I mean alot more than good or bad day. Like he finished his worksheet he gets one token. No work no tokens. Or maybe one token for starting and two for finishing.

As it is so recommended as a way to help mtivete add kids to do work in class , I was wondering if anyone has asked a teacher to provide it and what was the outcome? We are going to start doing this at home, but it seems as if school is where it would be most helpful.

Thanks for any and all responses opinions, etc.

Monkeyche