A couple of minor tips that have worked well for me:
a) non-metallic scrapers for nasty stuff: Small bits of formica (softer than steel, stiff and harder than fingernail). I have a few strips about 3/8 inch wide filed to different shapes on each end. I also keep a few bamboo chop sticks around, again ends shaped to different profiles to get into nooks and crannies but too soft to scratch paint or aluminum.
b) I use several of the solvents mentioned before but also keep a little alcohol around both rubbing alcohol and 'meths' - IOW denatured alcohol. The Kleenstrip 'natural' has a higher % of ethanol than most denatured alcohol and will dissolve or loosen things MS or Isopropyl will not. I never slobber this stuff on anything but will dampen a rag to see if it cleans something stubborn.
c) Almost forgot: eyelash brushes - the small round things. Real good for reaching into tight spots (ex RD cages) or for brushing crud out of wee threaded holes.