Yes, stainless can rust. But you can protect it very easily. Definitely do a search on this and other forums on rust, corrosion, lubricants, etc. A couple of years ago, I did and it paid off. I learned A LOT. There is a test posted all over the place where someone did an unofficial experiment with different products. It didn't have every protectant/lube available on the market, but it did have a lot. It concluded that for protection, Eezox was the best.
Then I did a little experiment of my own, imitating the original, only I used little steel strips and used some of the same products as in the original, and then also included a few more products not tested in the original. I found that indeed Eezox was a superb protectant, but so was Corrosion X and a little surprisingly, FP-10. Break-free was just a short step below these products. I was surprised that FP-10 was so good, because it was so much less toxic than any of the other products. I somehow found it hard to believe it would outperform so many others and hold its own with the other two already mentioned...but it did.
The Sentry products were a big disappointment. They fell far short of the mark. And just for the hell of it, I did some strips with the moly products they sell. I knew they were not protectants, but I wanted to see what would happen to them. Well, the strips treated with the moly seemed to corrode faster and to a worse degree than the untreated control strips. BUT, strangely the strips which were treated with the Sentry moly products and then coated with different protectant products actually resisted corrosion very well. It was as if the moly acted like a sponge and highly absorbed either the salt water and corroded at an accelerated rate, or the protectant which added to the displacement of the salt solution.
Now, I cannot attest to how well these products hold up in terms of staying on the metal and not rubbing off, especially dry, but I can tell you that generally I use the FP-10 for my guns because it is an excellent lube (and protectant) and is pretty non-toxic...it has no solvent. For my pocket knife, I used Eezox, which I let stand on it over-night before I rubbed off the residual. No rust problems, although my sweat is not cursed like that of many unfortunates. But I would have no problem using Corrosion X in its place.
One final note: long after my little experiment I purchased some Renaissance wax and tried it on my brother's Makarov, which is the only blued pistol between us. I was curious if the wax would hold up better than the liquid protectants. I haven't run any experiments on it, nor do I plan to, but his Mak is holding up just fine.
