Since you're not familiar with Hahn's prodects a breif primer. A tube is a white paper cylinder. Available in various calibers and length. Used to hold powder and ball or bullet. Very helpful when loading ahead of time. In the off season they could be stuck in the ground to grow miniature roses. Hope this helps.
Charlie's tubes are cylindrical cardboard, not paper, open on both ends and intended for use in Sharps. They are intended to rupture in the larger breech when fired and exit the muzzle. I doubt they would work very well in a muzzleloader if at all.
They only come in one diameter, .47" inside, don't know the OD, and various lengths. With the bottom sealed I doubt a percussion cap would burn through the cardboard tube. There are much better solutions for what you want.