The only thing on a bow that can rust is something made of steel. Same as anything else. On a bow that means the bolts or screws that hold modules or accessories. Bolt and screw threads are easy enough. A tbe of teflon goop used for pipe threads takes care of them. Even bowstring wax works. As for the tops or heads of those bolts? Who cares? It's not worth worrying about. It's just cosmetic. They rust sooner or later no matter what you put on them.