I've got a few spam cans of 7.62x39mm, love it, never have to worry about the ammo ever. LOL, don't think it would last long in the toilet tank though
Normally I just pack it into 50 cal cans w/ a few silica packets. If the seal looks good, I'll rub a little white lithium grease on it and close her up. If the seal looks like it's getting on in a years, I'll scrap off the top layer of rubber and crud with a butter knife, then spread some black silicone rubber gasket maker in a line around the edge. Give it an hour or two to mostly dry, and then close her on up. Worked great so far to preserve any ammo I've got laying around.