How do you clean/remove rust on the inside of chrome bumper?

I've had good luck with Lysol toilet bowl cleaner ( not the bleach kind). Works good and fast on bleeding through rust, just remember to wash it off real good three times, then WD40 it. If you do this on a work bench, put something down 1st, like sheet plastic and newspaper. Wash that stuff off real good, as it is an acid.