I am not against giving a child a potch when needed per se, but when is it needed? Also, how can you tell a parent/rebbe that they can hit a child, but regulate how hard, when and why?
When could a rebbe hit a child? When the child doesn’t do his homework? When the child talks during class? I don’t see a situation where a rebbe can legitimately hit a child. A lot of teachers do not have control over their kids (in their class), but smacking a child is not appropriate.