I had a buddy who didnt like the worn down spot in the blueing where the barrel rode in the gun rack. He re-blued the gun himself

I know he bought a kit and did it. Gun looks fine to me

shoots as good as it ever did
I know he had to remove the old blue before putting on the new. He took a rag and started to wipe down the spot with the blue remover, and a drip ran all the way down the barrel to the stock taking a strip of blueing with it

He told me the blue remover works really well

(kind of like the TarnX commercials) He ended up redoing the whole gun when he wanted to patch a little spot.