It would mean that if you applied an equal amount of each that one would be reduced fairly rapidly by about 15% in amount (worst case assumption) and then the remaining amounts would evaporate at the same rate. Given that there's less of one than the other it would be true that the one with the higher concentration would last longer, but given that neither one is very volatile they would both take quite awhile to evaporate and if you were not super careful with the amount you put on and accidentally got 15% more of the CLP applied then there wouldn't be any difference at all....the lubricant possessing the higher proportion of PAO (Mobil 1 synthetic automotive oil, 95% PAO by your recollection*) would last longer than the one with the lower proportion (CLP, 85% PAO by your recollection*).
In other words, if you applied a drop of synthetic motor oil (about 0.0500ml) and a drop of CLP that was accidentally 15 percent larger (about 0.0575ml) then the two products should stay in place equally long if evaporation was really the only issue.
I suspect that there's something other than evaporation at work.
A few possible explanations which I readily admit are speculative.
1. Synthetic motor oil is really cheap compared to gun oil. I suspect that makes a shooter feel free put a lot more of it on and that results in more of it being there later when they do a checkup.
2. I suspect that people feel really good about "cheating the system" and that alters their perception of the results of any "experiments" having to do with the relative evaporation rates between the expensive special purpose product and the cheap expedient. Especially given that it's doubtful that anyone is doing anything approaching a controlled, repeatable experiment from which to draw their conclusions.
3. There's some other mechanism besides evaporation that really does result in one product "disappearing" noticeably faster than the other one.