Here's how I did it:
I took a credit card (well, old library card- same difference) and got most of the goop off
I proceeded onto an old wash cloth (heh, it was a rag- but clean) and acetone nail polish remover
I finished it off by using the hanky and rubbing alcohol and nailpolish remover
This was to get the thermal pad off of a TaiSol 760092 heatsink/fan unit. Make absolutely sure that the pad is 100% off. If it isn't and there is still a film or something, using Arctic Silver 2 or any thermal grease will not be good because it will just be between some crap and the CPU...and that crap isn't going to conduct heat very well.
