Polish fiber optic at home?

Greetings All, I have a couple old Bausch & Lomb fiber optic bore scopes. The lenses they came with are good but the polished ends of fibers have some sort of corrosion that greatly reduces the light transmission. The steel ferrules at the ends rusted a bit so maybe it's rust on the fiber ends. Whatever it is it does not come off easily so I think I need to try some sort of abrasive. Is there a household product that might work? Like Bon-Ami? I don't want to ruin the scopes. One is cleaner than the other and the light transmission is much better so I know it's not the fibers themselves attenuating the light so much. Thanks, Eric R snow