Rifle, the quick load tubes are just vinyl with only one end open. You put a measured powder charge into the open end and the ball then seals off the opening. You can pinch the tube behind the ball and squeeze it out, then pour the powder straight into the chamber. I cut the ends of my .36 tubes off at an angle to make a sort of spout which helps me hit the chamber with the powder when I'm loading my pocket navy, which don't have a lot of clearance.
A year or so ago, I put some charged up ones down into a glass of water, left them overnight, then loaded and fired them. They all fired but there was some degradation in the powder from moisture in 3 or 4 of them. I did the test to see if they would be weatherproof enough for carrying in the pouch while hunting. I don't thing even total immersion, if only for a short duration,would hurt the powder any. I bought mine from Dixie. They had .36 caliber in white and .44 caliber in yellow. I guess you could make some out of any vinyl tubing, just use two balls instead of one and seal up both ends.
Here's a picture of my .36 pocket navy and the rig I carry it in. It's scratched up from wading through briars and brush but that's what I made it for. The belt pouch is divided to keep loaded tubes separated from empty ones. I can carry 35 reloads in it if I stack them just right. The Altoids tin of lube pills didn't come from that trading post you mentioned. I'd be too scared to go in THAT place!
DaveP, I've sealed caps with wax on the nipples but I wouldn't think putting wax inside the cup of the cap would work. I'd be afraid the wax would cushion the hammer strike and/or clog the nipple hole. Put in there liquid, it might kill the priming compound. The caps I have stored in a capper always have been o.k. but I carry a tin of caps in addition to the capper, anyway.
Steve