I read somewhere that this falls into the "Urban Myth" category. When cleaning your chrome with steel wool, you are cleaning it to remove rust from the chrome. When you remove the rust, you reveal fresh, bare metal. Bare metal rusts. It's not the artifacts of steel wool rusting, it's the steel you just cleaned and left bare. A good waxing after cleaning will help. I always use crumpled up aluminum foil for cleaning chrome. Cheap, available, easy and less likely to scratch.