Remembered this
thread while walking with the wife along the beach in Hilton
Head SC. She likes to explore and quickly found herself knee deep in sulfurous mud in a
marsh. After I pulled her out, she reached in to retrieve her
flip flop. When she pulled it out a silver ring she was wearing
had taken on a brownish grey
patina. I haven't
had time to clean the ring but the
patina wouldn't rub off.
So if anyone lives near a
marsh, you might want see what this does on a slug first.