I hadn't heard about Turtle Wax Chrome Polish and Rust Remover. The standard recommendation is to get a copper scouring pad. Supermarkets, Wal-Mart, etc, often carry them with the brand name "Chore Boy." Use one along with light oil (like 3-in-1, etc.), bore cleaner, kerosene, penetrating oil, mineral spirits or whatever similar materials you have around the house. I usually use bore cleaner. That will usually do about as good a job of surface rust removal as can be done. Don't get too enthusiastic with the Chore Boy. Wipe your gun off off with solvent and keep your guns waxed. Johnson's Paste Wax is excellent for that purpose.