If it is chrome, never, never ever use a metal polish or
anything labeled "Chrome Polish" Steel wool is a great way
to remove the chrome and expose the nickel plate underneath.
Many chrome platers I have asked have said that
Turtle Wax (green stuff) is what to use.
Said that, this only applies to Chrome plating that is in good condition.
If it is rusted, those nastier products I mentioned will work, but only temporary.