I can't remember exactly where it was (24 Campfire, or Accurate Shooter), but a few years (or more) back, one of the forum members did a long term test of the common firearms rust preventatives. IIRC, the test showed that Frog Lube was one of the best at preventing rust.
That being said, the OP asked what the "final step in bore cleaning" was. For me, it is easy. I don't clean my bores unless I absolutely have to. Even then, I almost immediately fire 10-20 fouling shots and then put the gun up. All of my guns are stored in a controlled temperature and humidity environment and as such, I have not had an issue with corrosion while storing. When hunting, the bores are always sealed by the bolt at one end and a "condom" on the other. The outsides get wiped down if the elements or humidity is bad, but that is it.