There are a couple of forums where guys have been brainwashed into "seasoning" their muzzleloader barrels. On one forum a guy likens a muzzleloader bore to a cast iron frying pan and claims it has to be "seasoned". Yep, FM; they went after you bad for having the gall to disagree with their use of holy Bore Butter.
Bore butter has its place in the lubing of conical bullets; end of story. Otherwise Bore Butter is the biggest scam that has ever been foisted on muzzleloader users.
One guy i met this hunting season slathered the bore of his Austin and Halleck rifle with Bore Butter before going off to Afghanistan for a year. When he got back the bore of his gun was rusted beyond salvage.