grind. I put it in my parts washer, that wasnt enough, so I then used denatured Alcohal and a number of bottle brushes/dish brushes/rags to scrub the runners out. Then flush with the hose...I did stuff it w/ rags and it kept most of the shavings in the front runners, some did get by. I wish I thought of having a chem dip, or cleaning before hand. Both GREAT tips.