Frankford Arsenal Quick-N-EZ, Ground Walnut Media, Treated, 7LB Container 331177

Cleaning brass by tumbling is the economical, safe first step in assembling quality handloads. Besides ensuring long life for the most valuable component of your ammunition, cleaning your brass will help reduce wear and tear on your expensive reloading dies, not to mention the chamber of your firearm. Grit and grime from uncleaned brass can become imbedded in the inner surfaces of your sizing dies, scratching and marring every subsequent case. The same grime can be expected to accelerate wear in the chamber and feeding system of your rifle or handgun.

Treated Walnut Media has brass polish in it.
NOTE:  Walnut cleans better than corn and corn polishes better than walnut.