I think perhaps the 'seasoning' moniker developed due to the 'seasoning' advertizing for Bore Butter, that thickness building up/accuracy destroying lip balm lube of a bunch of years back. The adjective "Seasoning' sounds good for a lube as it suggests that all lubing problems will be eliminated if the bore is seasoned first with this magic 'stuff'.
People know black powder fouls - some don't know that a tight load eliminates the fouling buildup and/or believe other people who say tight loads are difficult to load. People who are seeking the 'easy' way, are drawn to these advertizing lies. That is all it is - advertizing.
56% to 57% of the black powder charge results in solid waste after it's burned. Some of that 56% to 57% solid waste fouling is deposited on the walls of the bore, some/most, is blasted out the muzzle. IF you load a decently thick wet patch, whether it's wet with LB's metric Neestfoot oil, Track's mink oil, spit, WinterWinshiedWasherFluid+NeetsFootOil or whatever - the fouling that was left in the bore from the previous shot is EASILY pushed down the bore as the next patched ball is loaded. There are no mallets needed, there are no hammers needed - there are not steel rods needed. There is NO buildup - and NO need for seasoning.
If indeed you follow these easy suggestions and still have trouble, perhaps you need to have your barrel 'freshed' or your gun re-barreled as it MUST be badly pitted.
My daughter & Darrel's Kim, who are VERY strong and my wife who isn't very strong, load and shoot the same combinations we do - & WE are OLD men.
Pure lead balls
Pure cotton patching
Works