Flitz polish.

[Iroquois]

Well, 3 days of soaking in mineral spirits did the trick. I also found that brakekleen works instantly . Saved my brass. And my sanity.

 

[Iroquois]

I believe Flitz works similarly to Brasso, ie; it chemically alters the tarnish on brass (not dirt, soot, etc.) and makes it release its hold.
It must be wiped away, and turns the polishing cloth black.
Tumbling brass (coated with carbon, soot, burned and unburned powder residue) in media abrades the gunk off the cases.
The "polish" that you add to media really only acts as a lubricant, and keeps the gunk from being redeposited on the brass. (Put some of your polish on a rag and wipe a dirty case with it...not much will come off.)

Flitz and Brasso are great for keeping your buckles and buttons shiny, but for smoked up brass.......yeah, not so much.

Just my two cents.

 

[indyblue]

I believe Flitz works similarly to Brasso

I always thought it was a superfine abrasive polish similar to the Mothers mag wheel polish I use on my stainless exhaust tips on the Vette to keep them mirror shiny.

I believe Flitz can be used with a dremel wheel to safely lightly polish sear surfaces without risking damage like stoning can if done incorrectly by a novice.