I just picked up 20 used lug bolts. They need to have some dirt and a little surface rust removed so I can hit them with spray paint. Short of an ultrasonic parts cleaner (which I don't have access to), any suggestions? I've heard of using vinegar. I know I can use a wire brush or wire wheel on a drill or table grinder, but they're a pain to hold, and I always end up grinding off skin when I do that.