Late to the party as usual, but I've been using baking soda to "clean" chrome for a zillion years. Like Bon Ami, it doesn't scratch, but does remove any oxidation, road dust, etc. Wet the chrome, sprinkle baking soda on surface, rub with damp sponge, rinse.
I've also used the aluminum foil technique for removing very slight rust or pitting on chrome. Semi-successful - but cheaper than a new chrome job.
Tom