I dug out my old HO train set for the kids to play with. The brass track were oxidized, and I did a little research on what was the best way to clean them off and get them shiny again. One website recommended these 3M sanding sponges so I got one. It's perfect. Cleaned those tracks up perfectly, they look like new and the train is running again. The sponge is soft and easy to hold. My girls helped clean the tracks and were taking turns doing it. All in all I'm very happy with this.