I can't believe they are not selling lard in your grocery store's meat section. Its usually kept cool in the dairy case, near the butter and oleo. If you have solid shortening, like " Crisco", you can use that instead of lard.
Go ahead and use the Ballistol, but beware the smell. Olive Oil is probably cheaper and available, and makes a good base for mixing patch lubes. The thin oils make for less odor.
Ballistol is a lube, not a cleaner. Use soap and water to clean your BP guns. Plug the vent hole in flintlocks, or remove the nipple, for cleaning, and plug the hole where the nipple sets, and then pour soap and water in the barrel and let it SIT for 20-30 minutes. It needs to soak to let the detergent work. You don't need boiling, or even hot water. They are actually counter productive( that means "Bad ") for cleaning, as when you pour the water out of the barrel. rusting begins almost immediately. Use tepid, or air temperature water. Cold water works, but is hard on hands, and fingers. The barrel will not rust while you are drying it out with cleaning patches, ( and alcohol, to get the last moisture out by evaporating it out!). I recommend using a cleaning patch with detergent poured on it, to pump water through the barrel and in and out of a bucket of water in which you place the barrel, after removing it from your stock. If the barrel is pinned to your stock, then buy one of the adaptor kits that uses a fitting that either fits the vent hole, or replaces the nipple, has a hose that connects to your source of water and soap. Then pump the fluids in and out of the barrel. The high pressure flushing of the powder chamber and flash channel as well as the breechplug, will remove all residue, and alleviate the need to use any mechanical scrapers to clean those areas. Chang eht water a couple of times, and at least, use clean rinse water when you finish with the soap water to flush the barrel of gunk. Clean rinse water tells you when the barrel is actually clean.
If your drying patches show any dark streaks, you probably didn't let the soap and water soak the barrel long enough, and you can and should repeat the process. Some guns require a longer soak than others to get them clean. Water dissolves the salts and acids that are left behind in the powder residue. The Soap helps to break down the Carbon deposits. You want both out of the barrel. :hatsoff: