A friend of mine had problems with her sons being disruptive in class. So she told them flat-out if they didn't stop clowning around, she would start taking them to school and sit in their class with them. They knew damn well she would do it, too. The shenanigans came to a screeching halt.
If a parent isn't going to allow the school to discipline a kid, then the parent better be available to do. Otherwise, kick that kid right out of school.
Results so far are:
NO, the punishment doesn't fit the crime. 57 %
Yes, maybe she'll be scared straight. 34 %
Undecided. 8 %