Originally Posted by ependydad
My bumper is very rusty on the inside and it has never seen a sewer hose.
And like Tdbrn, there are all sorts of things inside that would catch a sewer hose if I even tried to put one in.
When looking at some of the models on the dealer lots when ordering ours, almost all of them had very rusty bumper tubes on the inside. I think a lot of the frames sit out in the weather before production and get rusted up.
There are Scotch-Brite pads available at most hardware stores that could be taped or screwed to a piece of 2x4 and shoved back and forth to clean the inside of the bumper. Then tie a rag (or someone mentioned a BBQ brush) to the 2x4, dip it in some Rustoleum and paint the inside.