Galahad,
The only effective way to use moly is impact coatingI(in a tumbler). The only paste or spray I've used is to put a fresh coat in the bbls prior to a range session. I push a wool mop out the muzzle spray it then pull it back to the throat then back out the muzzle so as not to get any in the chamber. I only moly five varmint rifles to extend the cleaning interval and make them easier to clean when I do. I didn't see any change in accuracy, and little change in velocity. Moly build up is how it works, it must coat the entire bore to produce the desired results. Anyone complaining about clumping is doing something wrong, this usually has to do with wax topcoats which I never use.
The drawback to moly is that it is hydroscopic, it can draw moisture from the air. All this means is you need to put a coat of oil in the bore when your done cleaning it. I've had no problems with rust or moisture simply by running an oiled mop through the bore after cleaning, then cleaning out the oil prior to the next use.
Moly gave me exactly what I wanted(longer cleaning interval) and minimal problems. If the bbls. last longer so much the better, but it's too soon to tell that.