Just re-read this thread & have a comment about petroleum products.
Some petroleum products, Vaseline, for instance is a petroleum wax, which does mix with BP fouling when used in bullet lubes.
The lube I use with it, is a mixture with beeswax. Since the beeswax is not a lube, ie: does not mix with BP fouling, it is the wax itself that does, to keep fouling soft.

60% beeswax, 40% Vaseline. More Beeswax, less Vas. makes stiffer lube.

Mixed by volume. I have used it on bullets (Lee's R.E.A.L. in a .45)in muzzleloaders as well, firing 10 shots on target, then loading a tight patched ball, saturated with
Track's Mink Oil without problem & putting that into the middle of the bullet group at 50yards. The bullets, driven by 80gr. 3F, shot to the sights of the RB's load with 70gr. 3F, thus the bullet lube was doing a good job.