Paddling or suspension for dress code violation ... way overboard. Just send the kids back home until the correct their clothing and not allow them into the prom.
the idea of paddling shocks me. is that even still permitted? i live in the oh-so-PC DC suburbs where i figure there would be law suits galore if someone laid a hand on a kid. And my kids all went to Catholic schools, where that was the norm back in my day.