I'm have used simple cleaning soulutions that we use for jewelery that will remove rouge which has some wax on locks but if I have a piece of jewelry that is caked with junk dirt and oil my new soultion is drano.I don't know if I would leave steel in it over night but gold and platinum are real safe and it works very well especially if heated.
It does give off a little smell that I am sure is not healthy.

monty