2 questions. 1) I have a new stainless steel revolver. I've cleaned the front of the cylinder with Hoppes and a bronze brush and it comes very clean. Will doing this repeatedly harm the surface? 2) I have an aluminum revolver (including the cylinder) with a matt finish that I haven't fired yet. Aluminum is softer than stainless (I think). What is the safest way to clean the front of this cylinder without changing the finish?