I used to use CLP religiously. However I started having fail to feed and fail to eject problem. Granted part of this is likely caused by not only the fact that I used CLP religiously, but also liberally. After a little carbon buildup soetimes I would have a "goo" in certain areas around the bolt carrier.
Anyway in the mean time I started experimenting with different mixtures of Mobil 1 (5w-40, for diesels), Marvel Mystery Oil, CLP and Automatic Transmission Fluid.
Right now my sweet spot mixture seems to be 2pt Mobil1, 2pt Marvel, 1p ATF, and a little CLP in the mix...if I feel like it.
What I have found is Marvel cuts through build up very well, without damaging parts, and a combination of ATF and/or Mobil seems to lube my rifles better than CLP does.
Not only that, but it's far cheaper than CLP. Cheap enough I can literally mix up whole vats of the stuff. I haven't tried to run a diesel truck off of CLP yet, but somehow I don't imagine it will do as well as Mobil 1 will. And I won't even discuss ATF, it's so durable.
I guess change every 3000mi, or 7000 rounds, whichever comes first.