- Jun 28, 2019
- LaCrescent, MN
I bought a Harbor Freight sonic cleaner to do 20 Grendel cases only. I used distilled water and the recommended 1/4 tsp. of powdered cleaner, and ran 4 times. Twice with heat, and added another 1/4 tsp. of cleaner. Result is the brass looks like I never ran it! See the pic, before and after neck looks unchanged.