Something that has always worked for me is rather simple, grounding. I have dealt with subs who are pain sluts and actually act up just to get attention. Whaen this occurs I restrict them to their room for the weekend, or a longer period, and let them think about the fact that I would be as willing to reward them with pain as they seem to want me to be to punish them. It is especially effective if their is an activity planned for that time.