I've used an aviation version of CorrosionX on certain areas of my airplane that aren't painted, epoxied or zinc chromated where corrosion could potentially occur. It has inhibited corrosion and protected bare metal from my own personal experience. Some aircraft owners with aluminum airframes will have the interiors of their airframes CorrosionX'ed to ward off corrosion in cases where the aluminum isn't coated with anything else inside them. Their airplanes will "weep" CorrosionX for a couple of weeks afterward.
I've also used it on a couple of truck frames, and it seemed to work. In Iowa, it takes a lot to keep the brine from eating everything whether it is coated or not. I keep a couple of cans around the shop on the rare occasion that I cannot oil, paint or powdercoat something.
Hope this helps.