Don, I'm not really one to pass............
as one who has found out the "right way".
I've applied the hBN using alcohol to the barrel. Matter of fact, I have a small Dewey's bottle w/dissolved hBN in it on my workbench right now. That application seems to hold it in the bore adequately, and in RFs I've just pushed a dry patch through the bore. I have another bottle w/MPO7 and hBN dissolved in IT, too, and I clean just the way I always have, using the liquid on patches.
I plan to try a third way using a spray, by cleaning the barrel as surgically clean as possible, drying it out, and then using a spray applicator. Once I get the applications dry, then I'll begin using the CFs, and dry-patching as I have on the RFs.
I've also taken a stab at coating some bullets, but I believe I need to get some other equipment to do an adequate job.
Since I've had some limitations w/transportation, I haven't had the opportunity to do as many comparisons as I'd like.
That said, the CF barrels seem pleased w/the "old" way, coupled w/the "new" additive.
Only thing left is to get to the fine-tuning. HTH