Corn Cob media is softer than walnut shells and is great for brass cleaning and polishing. This is not treated with any chemicals. Size is 20 grit (about .0525"). Low residue too, not much dust generated. This is what we use in our shop for cleaning up small batches of once fired brass. For best results add in a couple of tablespoons of liquid Nu Finish or Turtle wax and 1 tablespoon of Scratch & Swirl Remover while running and without any brass. Run for about 30 minutes so it is well mixed, then add in your brass.
The photo shows about how much 4 lbs (about 7 pints) will fill a Frankford Arsenal Quick-N-Easy Tumbler. The other picture shows how it is bulk packaged. This does not come with the tumbler bowl.
100% organic and biodgradable. Highly absorbent and does not contain silica.