For the claying, I'll squeeze/mold it into pieces that'll fit where I need to use them. For the polishing, I'll use a stick (e.g., sharpened swab stick or toothpick) to work my MF in there. Gotta be careful you don't let the stick penetrate the MF and mar the surface though. Sometimes I'll fray the ends of such a stick so make a sort of "brush". I'll soak this with QD to soften it and use that for some of the more aggressive work. Don't try that on soft paint though. FWIW, I like to work tight spots with magnification.
Heh heh the *real* answer (in my book) is to debadge 'em