However, if the barrel is pitted, no manner of cleaning, scrubbing, or steel-wooling will remove the pitting.
It will shoot, and will perform to some limited degree of accuracy, but a pitted barrel remains a pitted barrel.
If it is offered CHEAPLY, think twice before purchasing! This is absolutely no way to begin the wonderful experience of the uniqueness of flintlocks! Having them function properly isn't that difficult.
The heart of a flintlock is the lock itself. If the lock isn't tuned properly, if the flint isn't sharp and striking the frizzen with sparks flashing downward into the pan, if the pan is overfilled with priming powder, and, if the touch hole isn't properly cleared to the main charge, then, the result of pulling the trigger will be a serious disappointment!
There is absolutely nothing magical about using flintlock weapons, it is simply common sense. Our Revolutionary War recounts the importance of Pennsylvania flintlock rifle regiments. Their success with using rifles with flintlocks didn't require "how-to-use" manuals. It's the same today.