Can you remove tarnish on this aluminum kitchen tool?

I purchased one of these aluminum meat pounders about a year ago (http://www.surlatable.com/product/aluminum+meat+pounder.do). This week, after using it on raw chicken I got lazy and tossed the sucker into the dishwasher. When it came out the next morning, it was covered in a dark gray tarnish that seems to rub off on anything it gets near. Is it possible to clean this thing—or have I turned it into garbage?