Here's a tip......heat the surface and apply Frog Lube. Allow it to soak in for 10min or so then polish the Froglube in with 0000 Steel Wool. It will remove all the rust and leave the metal/finish protected from rusting in the future.
Here's a pic of my Sister n Laws Bersa which should brought to me for cleaning after allowing it to get all rusty.
Blame any misspellings on Tapatalk