If you're still cleaning your brass old school style (like me) with crushed treated walnut hulls or equivalent, and a vibrating case tumbler, I found (internet)a way to inexpensively rejuvenate the media.
Just add about a half a cap full of liquid 'NuFinish' car polish. I add the polish and run the tumbler empty for about 10 mins and you're good to go.

They do have several additives specifically for crushed media too, that aren't expensive.

I really like the Frankfort aresenal stuff. I've also dabbled with Flitz, and tried a run with a little pat of Mothers Aluminum polish

All worked very well, though Frankfort is by far the easiest. Squirt and go.

Another thing to do is to put dryer sheets on top of the center post (my tumbler is a dillon) and it will take a lot of the dust and fine cleaning particles out with it.

I have had luck with walnut bird cage material from Petsmart. 15# for $14. I can't tell the difference when using it. My philosophy is clean, not shiny, so YMMV.