Whatever is in a plastic bottle or metal can or whatever that says "polish" on it. The condition of the chrome has a lot more to do with it, than what snake oil you use to clean it with.
Double Zero (00) is too harsh-- use Quad Zero (0000) I've always used Mother's polish, or eagle one. They both work great.
If it is real dirty I use S.O.S. pads, they have polish in them so the water beads when you are done. I found an example the first light was part of this pair and dirty as hell (patina?) the second pair of lights is after nothing than S.O.S. pad and water, those brown lines are not rist or scratches, the chrome is crazed and that is the copper showing though. I dearly love old chrome.
I have used CLR on a soft cloth on chrome that is starting to "go". Steel wool in any grade removes the very thin chrome layer exposing just the nickel underneath, or copper under that. I remove old bumper stickers parking permits, reflector tape, etc. with just a "sharpened" tongue depressor or popsicle stick.
I was just gonna say barkeepers friend, with a 0000 steel wool, and then polish out any swirls with chrome polish.
Another cheap product that works well is the GOJO hand cleaner with pumice. Residue washes off nicely too. ---John
I'm with DrJ in that steel wool wears the chrome thin exposing the nickel underneath, metal on metal contact should be avoided (although if you've got a bumper that's totally brown with rust or something that's really trashed, go for it, it'll look better for a while at least) I like to use buffing compound, the same stuff I'd use to buff out a wetsanded paint job. A tongue depressor to scrape heavy crust off first sounds like a good idea too, I'll try that.
If your looking at cleaning newer chrome then cleaners like windex and then a soft wax or cleaner wax. Nothing thats a polish and certainly not any kind of steel wool. Anything even slightly abrasive can leave swirls and scratches in nice chrome. Older chrome thats already scratched is best to avoid abrasives as well so that the chrome isn't further removed. The chrome plating is extremely thin. Most of the thickness of plating is the Nickel. Very fine 0000 steel wool is handy when its really gummed up but it should be used carefully.
I use toothpaste (Colgate is the most aggressive) to polish/finish-sand Alabaster stone sculptures. It will definitely "sand" the chrome off! Anything called "polish" you should consider "liquid sandpaper" and use it only on things you want to remove a layer of material from. You know, like the old lacquer paint job that's been "polished" right down to the primer?
Wash off dirt and grease first. Steel wool is too harsh, I use a copper scrubby pad (3 for a $1 buck at the dollar store) with some Pledge or spray furniture wax. This gets off rust and crud. Wipe clean Then polish up with Flitz, Simichrome or your favorite chrome polish.
Kroil is an amazing product, (better than PB Blaster, WD-40, etc.) but I've been unable to find any locally. I use to get it from a contractor friend, but have lost touch with him.....any ideas for a source?
i use brass wool & car wax,cleans the rust off & protects too,----2 birds-1 stone thing, it won't remove pits or major scratches {'cause it softer than steel/chrome}it's pretty good at removing 'fly sh*t' rust specks, wear gloves 'cause that sh*t will stain the hell out of your hands almost as bad as polishing aluminum,