Cheap
Okay, I'm a brass rat, too, and have tried a lot of things over the past 35 years of reloading.
If you're doing this stuff in quantity, and cash is tight, get a big vibratory cleaner with a warranty (I've burnt out a few). Find a cheap source of media (I get 40-pound bags of corncob at WW Grainger's for about $25). Find a cheap additive (Nu-Finish is the cheapest I've found, and Walmart sells it). Recycle your worn media when it gets too dirty to be effective anymore (I use mine on my icy driveway instead of sand).
Nu-Finish gives you the very mild abrasion you need to get real crud off. I let my vibratory cleaner run overnight or for a full workday and the stuff comes out looking like gold
. Auto waxes do just that - they wax - they can coat the tarnish that's already there. Give it a try sometime - try some Turtle Wax in new media and test it against Nu-Finish in new media. I do believe in the Nu-Finish as the best and cheapest solution. No debate on ammonia.
Yes, it can clump up when first introduced to media, but if you let it break up while running without brass OR smoosh up the clumps by hand and let it break down a bit, as another guy says, no problems.
I bought a pound of jeweler's rouge from Powder Valley for about $12 some years ago and add a teaspoon to a load if the stuff looks like brass left over from WWI. That's never a requirement, but it speeds up the process for brass that looks hopeless. Nu-Finish by itself will still get you there.
A 40-pound bag of cheap media and one bottle of Nu-Finish will go a
long way - for under $35 total - and I load maybe 10-12 thousand rounds a year.