WARNING
Most compounds that can take off paint are toxic in some way or another. If you are using these chems do take care with their use and disposal.
Pine sol: soak a day or so and it removes paint from metal minis and softens plastic minis and bases and then melts them. Not too toxic and some may equate the scent to cleanliness.
Brake fluid: One of my favorites cause It won’t eat the plastic minis[for the first few months]. if you soak the mini in the brake fluid for a few days you can toothbrush away the paint. It does have an odor and can be difficult to clean off completely
Simple Green. Strips acrylic paint and fresh primer won’t eat Games workshop plastic [or Fortress figure’s resin[I think].
Acetone [Nail polish remover’s main ingredient]:
Pro: Potent, fast, eats glue and epoxy, can strip latex paint off a mage knight in 30 seconds.[pinesol takes days.]
con: Toxic, fumey, flamable, smelly, bad to skin, Devastates normal plastic, to get full strength you have to go to bueaty or hardware store.
BTW
1. If the mini has some very small crevasses you may need a toothpick to get in the small openings
2. Avoid mixing these chemicals together. I got no Idea what may happen if you do mix them. ....ok rubbing alchohol and amonia = lung burning fumes
3. If at all possible put minis into a glass jar and let them soak OUTSIDE your home. Few things eat glass and the possible fumes are best kept outside your dwelling. { I had to use a Gallon pickle jar to clean the tire glue[ a THICK black cyanocrylate based glue in the superglue/crazyglue/zap-a-gap family of glue] off of the WotC Black dragon I bought from a friend who had NO modeling experience and tried to put it together.}
4. Wash minis thoroughly after cleaning them of paint.
5. If the Mini has a lot of glue / epoxy putty work taking the paint of will likely dissolve the putty and glue off.
or hardware store.