I'm not a fan of the EPA,but a lot of the really effective solvents share the problem of being very carcinogenic.Carbon tetrachloride is an old one.Trichlorethane is just not real good for you.The ingredient in Hoppes was nitrobenzene.Your poor liver is happier without this stuff.
If you go to the Schuemann barrel site,look up his "cleaning" page,he explains how chlorinated hydrocarbons are not so good for stainless steels that are sulphurized.
A lot of excellent tapping fluids,like Relton's Rapid Tap,were reformulated for the same reasons.