I have only been rolling (inside prepping) for the past year and a half, since we started going to some Maxxis races. I bought a couple of sets of used, prepped tires from a pretty good tire guy who told me this about rolling them:
First, he gave me the name of an inside prep to use. He told me how many cc's to use on new tires, and how much to use when re-rolling them, and when to re-roll. And to roll them for 24 hours. So I did, and we have been pretty good on them. Inside preps, I don't think, are quite like external preps. No, you don't just wipe the inside of the tire with a sponge. And evidently it takes much longer for the inside of the tire to absorb preps.
There are so many good tire guys who really know this stuff here on Bobs who will be filling in the blanks much better than I can. I'm interested in reading the responses.