Re: BRASSO
The vinegar is a mild acid, and this hels remove the tarnish. I have also added diluted CLR, which is especially effective.
Once, by accident, I turned off the tumbler with the brass and CLR-dampened media and left the brass in there overnight.
When I separated the brass the next day, it had acquired a dull olive green patina which was durable enough to stand up to handloading and firing, but wiped off easily with some jeweler's rouge on a cloth. Copper bullets came out the same and ammo made from those components had this same olive green sorta camo effect.
It appears to have zero effect on performance. I have mentioned this here before, a few years back when it first happened.
OTOH products containing ammonia have been accused of chemically altering the crystalline structure of the brass, weakening it. Brasso contains ammonia. A good alternative homemade brass polish can be made by mixing up a paste of vingar and baking soda. The sodium and vingar (acetic acid AKA ethanolic acid) combine to make a quite effective brass polish that does not contain ammonia.
Greg