Floss didn't work, but I took the scoops off last friday with an Olfa knife and tidied up the gunk with a rubber stripe remover wheel I had left over from another job. It is much better.
I got the new box installed on sunday afternoon. I scored on that deal. I found a perfect box off an old guy truck that has spray in liner, and not a mark on it. I don't think he ever put anything the box! It came with a bumper and all the lights. Did I mention it was free? The guy I got it from swapped me for the ugly old flatdeck on my truck. He also did the swap over while I did a rework of the wiring on my truck.
Winner winner chicken dinner!