It's never advisable to choke yourself. I personally would not advise anyone else to choke me either.
I have read stories about 2 or 3 kids passing away from playing the choking game, with in weeks of each other, at the same school. It is horrible. 3 people died, total, the 4 years I was in high school, and they were all in car wrecks.
I don't have kids and I can not even imagine... Horrible.