Rust on stock pipes!!

Did a search and saw a note about turtle wax chrome cleaner and rust remover. I've got a few spots turning up and I'm an all weather rider and the bike sleeps in the 1st floor garage of my building. It's open but the floor space is bigger than a foot ball field so it's not getting rained on when it's parked. Ok. So because I can't stroll down to autozone and the HD shop is South Korea does not do a full cleaning when I drop off for service I need some advice. How the hell do I get this off my mufflers and can I stop it from coming back? It's a 2015 RGS...is this under Warenty??