The problem with the DIY kits out there is they give you a compound and a pollish.If there really caked up with oxidation sanding them out might be your only option as the hand rubbing them with compound is only gonna do so much,not enough abrasives and not enough heat.Plus,sanding and buffing them gets all the scratches and bug damage out if cut down good enough.Or just have them cleared.Either way works like Josh said.