Methylene cloride based strippers do not remove blueing. Blueing is a rusting process, not a varnishing process. No one would ever refer to these strippers as mild, and your safe, yearly exposure to methylene cloride is zero.
It lives in strippers, spray paints, and industrial cleaning processes. Zip Strip, and Ditzler Aircraft stripper, are two examples. Follow the directions on the can, remembering that it is about the worst carcinogen known to man, and that it is going to devour any varnish it or it's fumes get near.
The "mild" strippers use acidic components in a water based formula-I bet money they would be top notch blueing removers, but, haven't tried.
I do know for sure that ketchup, either Heinz or generic brands, makes a great blueing remover.
Don't ask me how I know this.
Best,
Ted
