Just don't let your wife find out...
I have found this to be the easiest and cheapest way to clean dirty range brass and it really does work...
I take two old cotton socks (no holes) put about 50 or so cases in one. Tie the end in a knot. Then put it inside the other sock and use a plastic zip tie to close it up tight. Throw it in the washing machine with some old towels I use to dry the car and anything else that might need a quick washing , add detergent and let it go. I think the front loaders might do a better job than the old top loaders as the front loaders tumble the socks around. I could not believe my eyes when I took them out. Not polished much, but all that dirt, grit and most all the tarnish was gone. Try it, it works great. Just don't let your wife know what you're up to.