Hi Bruce G.
I am hopeless old fashioned I guess. I have tried vinegar, various rust removal liquids, and CLR, but I always seem to go back to elbow grease wire brushes and abrasives. I may have to try electrolysis at some point. I do know that I have not been happy with the chemical treatments because they don’t get rid of the metal staining and I normally have to do some abrasive work anyway to flatten soles and sides and generally improve the appearance of the surfaces. This probably makes some purists cringe but my tools are users.