I have read a ton of threads on chrome and trying to get that old shine back. This is my method after some testing. Step one soak a piece of paper towel in CLR 5 to 10 minutes on the piece of chrome you are working on. In this case I chose a big ass bumper because I was testing other methods and working on this so i needed something large. After it soaks for that couple of minutes on the rusty chrome I have been using a sharp razor blade and scraping all the scale rust off of the chrome. After scraping it's onto the 0000 steel wool and start working it over. I am doing this all by hand other then the final buff. I am not set on a compound yet I am testing some turtle chrome polish and I have some wizard on order. The test piece removal just to give you an idea of the condition of the car it was picked off of in the boneyard.