I carried a 1911 during my shipboard time in the Navy as a rover. No special coatings, paints or anything...just kept it oiled. No rust in 5 years on any of the 1911's that were in the regular watch rotations. My personal experience is that the extra stuff is not really needed.
"The sword that cuts down evil is the sword that gives life"
*10 Ring, MBR and Reloading Clubs: #436*