The way I understand it, the additives in the carrier (grease OR oil) bond to the metal, and actually displace gunk from the pores in the metal. I used the oil in the barrel of my FAL, and it did exactly what the advertisements said it would do. The groups did become more consistent, and cleaning got easier. I still use the grease on my pistol slides, but for my rifles (esp. the precision stuff) I've switched to EEZOX. same protection as the Tetra, is an awesome cleaner, and dries without leaving residue (important when you realize most cold-bore deviation is caused by the excess lube in the barrel).
The neat thing about EEZOX is that, after it dries, you can put ANY OTHER OIL on it, and the other oil just beads up. It does this even after a cleaning with Sweet's solvent! No, it's not permanent, but it does last, and not even my trunk guns show any rust. I don't get nearly the lint-in-barrel problem I used to, either. My advice: EEZOX for cleaning/lube, Tetra grease for slides and heavy-friction points.