The active ingredient in fingernail polish remover and paint remove is a solvent named Acetone (found in hardware departments). In it's raw form it will eat away paint in a blink of the eye. It won't harm bluing, but will dissapate oil so be sure to reoil the cleaned part after you remove the paint (the bluing will look dull till you reapply the oil).
Caution: DON'T use acetone on most plastics or polymers. It will dissolve common plastics. Keep it away front sight inserts. The smooth plastic surface will be etched to a rough surface and the color will dull.
[This message has been edited by Majic (edited 04-15-2004).]