Purple Metal Polish

Anybody tried this for polishing cases? I've been using Dillon's polish, but I was not impressed. I got this from a guy at work and tried it today. Man, this stuff works like crazy! I had some 9mm cases that I picked up over the weekend, and they were badly tarnished. This stuff cleaned them right up. This stuff is kinda pricey, but so is the Dillon's.

http://www.californiacustom.com/purple_metal_polish.html

http://www.californiacustom.com/images/products/purple-metal-polish.jpg

I tumbled the cases for about two hours in walnut media, with a couple tablespoons of Purple.