I just bought a Zassenhaus on eBay that needed some considerable cleaning (some rust, and enamel flaking off), and I used a Dremel mototool for the bulk of it. I used a brass brush bit for the rough cleaning on the burr areas, and polished up the 'bowl' with a buffing wheel attachment with a little baking soda. Seems to grind okay, but I want to go back over the burr edges with a diamond tip to hone them a little.