I took my banjo to a buddy to refret some frets. He tried cleaning up some metal parts and also an ivoroid button. He used a high strength polish on the arm rest, and brake cleaner on the ivoroid button. Neither polish or cleaner worked. The metal armrest has eroded and caused a rough patch of brass showing. The ivoroid button has turned green. This is all because of the acid in my hands. I'm bad for not wiping up afterwards, but I told him I kind of like that "old worn" look.
I also take a lot of medicine, which could contribute to it. He was really surprised how my sweat ruined an armrest and a tuner button.
Does anybody else deal with the acidic hand sweat?