T.F.
The only thing that has worked for my two older children is to wear regular underpants. Pullups are just like diapers and don't give them the nagging feeling of being wet. Whereas if you use underpants, when they get wet, they know it. No doubt. My best advice to you is to ditch the pullups, diapers, etc and put him underpants. Buy him some of his favorite character ones that he'll enjoy wearing and won't want to wet. You may have a lot of laundry for the first week but he'll feel like a big boy wearing them and won't have the crutch of a diaper. :) Good luck!