What do you use to keep the silver edges clean on your ip4? I can just wipe my screen with a micro fiber cloth and I'm good to go. But when I wipe the silver with the cloth it leaves "smear" marks. If you use a damp cloth, some of the smearing goes away but not all of it. I'm really not a clean freak at all and I know it's going to get prints on it all the time. But u figured somebody would know how to keep the silver trim nice at least for a while.