I don't see how the punishment fits the crime at all. If you want to stop destructive behavior throughout an adolescents life, you must educate them.
You educate children through schooling, through sitting down with them and explaining, through making them talk to who they bullied and understand how the other person feels. You don't make him an a-social sociopath learning nothing from "homeschooling", casting him out of society, and providing no form of positive reinforcement.