I have an ancient Delta bandsaw that had some strange 'stains' in a few places. They resisted removal by everything I tried, until, for some strange reason, I tried Never-Dull. They came right off. I've tried NeverDull several times since in a similar situation and it didn't do a thing.
Speaking of things used not as originally intended... Mothers mag & wheel polish actually works really well on clear if you rub in with fingers so you can control pressure. Follow up with a good wax, I've gotten excellent luster out of dull paint, and even removes stains really well. Didn't even put a dent in that stain up there ^^