That's completely different Balish, when you pass out your body will correct itself. I do not believe that's harmful. My cousin's son did this and the doctor told her to ignore the behavior, when he realized that she wasn't going to react he'd stop and he did.

With the choking game the kids are using something, a rope, belt etc to assist them. In the case I saw, the boy was unable to to release it as he passed out.