A few decades back, before the benevolent government and common carriers decided the public could be gouged if they called it an explosive, black was available everywhere and there was no need for substitutes, although more than a few folks resorted to sugar powder. I remember black powder being out on store shelves in general stores, although that was late 1950's or early 1960's. I heard some folks bragging recently about how it is easier to buy dynamite in some places than black powder. Around 1994, I met a man at the High Plains Rendezvous for whom Pyrodex was a Godsend, his wife had a state day care license and they showed up for surprise inspections a few times a year. Since the day care was in their home, their entire house was subject to the inspection. No volatile chemicals, no explosives, no volatile paints, no denatured alcohol, or paint thinner, not even gasoline for the mower and no propane for the grill. But irrationally, he could have firearms, ammo, reloading components, and lastly, he could have Pyrodex because it was not classed as an explosive.
The line must be drawn somewhere. Do we exclude folks whose "primitive clothes" was sewn on a machine, or whose tents are made of sunforger instead of cotton canvas, or linen. What about the modern steel in their gun barrels, or the fruit of the looms under their primitive clothes. Should we thrown them out because they store their guns soaked in Ballistol, bore butter or some other modern rust preventative synthetic goo.