Punish however you deem necessary. Liz my child knows that when she misbehaves she will get a spanking if the offence is severe. If you tell your kids in advance that if they constantly dont behave they will get a 'bare butt spanking' (as you seem to have done), then if they misbehave they KNOW the punishment they will get. Theyre practically giving themselves the inevitable spanking if they then do misbehave. I havent spanked on the bare though, but if you think you should, then discipline the chid lovingly the way you feel is best, whether that be time out, explaining to or spanking.