I don't know anything about Butch's Bore Shine. So, no I was not speaking about it. If you have been following discussions here for any length of time, you should understand that petroleum based oils have no place inside the bore. You can use them to lubricate the internal action parts, the trigger, etc. but don't put it in the barrel. There are vegetable based oils, and Mineral based oils out there that work better with black powder, and are therefore suitable for use in the barrel of a Mler. I have not yet heard of a substitute powder that will work well with petroleum based oils in the barrel, either.
Burning petroleum based oils inside the barrel of a MLer using BP will produce tars and unburned oil that congeals, and just gets thicker and thicker, and sticker the more times the gun is fired. I don't believe the temperature of caps or priming powder is hot enough, LONG ENOUGH, to burn out the tars.
That is the reason I recommend flushing MLers out with alcohol after any length of time in storage, with any oil or grease product use- petroleum, mineral, or vegetable based. I do believe that vegetable based oils DO burn better than the Petroleum based oils will, but I would rather not lose a shot on game in the field by hoping I am right on that score, when I can easily flush my barrel with alcohol, and eliminate the concern entirely. I do this flushing at home, when I pull the gun out of the gunroom to take to the range or field. After flushing, I dry the barrel with dry cleaning patches, then run a lightly oiled patch down the barrel to keep the barrel free of rust during transportation to the field or range. At the range or field, I run a dry patch down the barrel to soak up the thin layer of oil down the barrel, before pouring my first powder charge down the barrel.
Concern should be given to any rifle you own that has a smaller than bore diameter " Powder Chamber", as its very hard to clean those smaller chamber if you don't have the correct sized brush/jag for that job. Many owners of Lyman GPR and the T/C rifles don't even know they have such a powder chamber at the back of the breech. The same for older CVAs, and rifles sold through Cabelas and other distributors, which are made in Italy and Spain. Depending on the bore diameter, the powder chamber can be as small as .25 caliber to as large as 33 caliber. A few very large bore guns will have a powder chamber that is .45-.50 caliber. You have to spend some time acquiring the correct size equipment to clean these if you intend to shoot a lot of rounds during a shooting session.
These guns also have narrow flash channels that lead from the vent hole( or nipple, in percussion models) to the center of the back of the powder chamber. These channels must also be kept clean, and the shooter needs pipe cleaners, and needs to visually check the channel to see that it has no blockages due to casting burrs. We have seen many of these guns with clear barrels, but with flash channels that are completely plugs, because they were not inspected and cleaned properly at some point. Shooting of priming powder in your pan is just not going to clean that flash channel. It may even add residue to the existing stuff, and contribute to blockages. A Vent pick, or nipple wire can be used to clear these channels, if they are the correct size to fit through the vent hole and traverse the length of the channels.
The hole in the back or "bottom" of the powder chambers on these guns tend to be too small. That is often where a blockage will occur. It is next to impossible to clear this blockage from the vent hole or the clean out hole accessed by removing the clean out screw if it exists. You have to attack it from the muzzle of the gun with scrapers, and solvents. Sometimes, you can fill the channel up with priming powder, poured and pushed through the vent hole, and then blow out the obstruction. Its always worth a try. But, then, clean the flash channel, and powder chamber properly by flushing them with alcohol.
I always recommend the owners of new guns with these powder chambers take the clean out screw out of the gun, and use a properly fitted drill bit to "ream" the channel of any burrs. I also believe that if you can use a slightly larger bit, to open up(widen) the channel, without compromising the threads for the clean-out screw, that this will help elongate the small hole at the bottom of the powder chamber, decreasing the chances for a blockage there. The smoother the flash channel, and the wider in diameter the channel is, the better the ignition will be.