The advice to use Naval Jelly is absolutely something you do NOT want to do if you goal is to freshen up the original finish.
Naval Jelly is a phosphoric acid based rust remover that will remove the blue or patina, and replace it with a dull gray with white phosphate residue. The frosted etched surface it leaves behind even makes it unsuitable for use in a complete rebluing process unless you want to do a lot of polishing or end up with a dull matte finish. Save the Naval Jelly for brake drums and plows.
