Comment by stonesweep

Many hobbiest collectors (in my travels, which is of course my experiences) use 100% acetone soak on metals. A brand known as Renaissance Wax is a popular microcrystalline coating used to inhibit reactions (ive been told its popular with knifemakers as well). Ketchup is a great copper/bronze/brass cleaner while we're here, not so hot on nickel, sort of ok on silver. Titanium and zirconium just don't care how you clean them, aluminum is ketchup friendly.