Stainless steel isn't rust proof, it's rust resistant. I've used steel wool (0000) with a bit of WD40 many times and it will remove rust handily, leaving any blue that may remain(on blued weapons)if used gently. I've never seen any problem with steel wool leaving a residue on stainless that had any effect on rusting.. I prefer to use the stainless steel scrubbing pads found at grocery stores. They look courser than fine steel wool and are a bit 'curly' looking, but they are of softer material than the carbon steel in steel wool. So they are a bit gentler on the finish.. On stainless the problem is to match the finish you have created in removing the rust, with the finish already present on the weapon. One caution, the scrubbing pad I am refering to does NOT contain any soaps or detergents.