I learned about Bronze Wool here on this forum. Steel wool breaks down and can leave traces of steel fibers traped in the wood finish, which can oxidize causing stains. Bronze Wool is stable and at least as gentle 0000 Steel Wool, maybe gentler. It can also be used in combination with a penetrating oil to remove minor surface rust from blued firearms. I bought some at Ace Hardware and have found it very useful. Sonora