Forcing someone to have diaper rash, and use that as a punishment, seems kind of cruel to me. I mean, when I've not been careful, and gotten close to a full-blown rash - mostly, I get a substantial dose of skin irritation - I take a break from diapers or spending time in wet or messy diapers. And, actually, the irritation comes more from urine, and not messing. If it begins to burn, I get out of messy diapers PDQ! To force someone to have to endure a full-blown diaper rash would be terribly uncomfortable, if not painful, for too long a period of time. But, then, it depends upon the scope of the dom-sub relationship and what activities that includes. If it's just a part of diaper domination, I guess you simply have to buck up and deal with it. Not for those with a low threshold toward diaper discomforts...