Season your fying pan. There is no truth in doing this to a rifle barrel. When cleaning, you must get back to steel, then protect that steel with oil, grease or other preservative substance - or you will cause pits/rust/iron cancer.

There was some writing by those who get paid by the word, about this seasoning you barrel. Perhaps it came about when using loose ball/patch combinations with some of the crap lubes sold to unsuspecting individuals - like Bore Butter (most famous one - Lube 1000 is another - which seems to be little more than lip balm with some Wintergreen oil to make it smell nice.

In the loose ball/patch combinations, this crap would actually build up in the grooves over a number of shots and indeed, would wreck any accuracy that was there prior. Then trying to remove it by pushing patches up and down, merely smoothed it out, so some live wire or other garbage producer, figured it was seasoning, or some such foolishness like that and wrote it up, only to be repeated by others who are still on a long learning streak.

One guy on another BP form tested it due to some possibly negative verbiage I might have used, then had to use carb cleaner to actually cut it and remove it from his bore, along with a bronze brush. Of course, there is/was BP fouling in the thick brown tar-like buildup that water, even hot water would not touch.

Please do not do it nor attempt to do it.

Anti-seize grease can be put on breech threads, or normal oil is fine.

ML's need to be cleaned, as in ALL fouling removed. BP is dissolved by cold or cool water. No solvents are needed - water is BP solvent. Boiling hot water causes FLASH rusting to many barrel steels used in muzzleloading rifles and shotguns. Flash rusting is accumulative & results in pitting one end to the other.

Holland and Holland says to use Cool or Cold tap water only.