20 gallon metal can is what is/was commonly used on the long glacier traverses. The type with a lid that crimps down. When you get to the airdrop and get to your can you can pound it flat with a rock, and either then carry the flattened can out or (I wouldn't recommend this but it has unfortunately been done in the past) chuck it down a crevasse where it won't pop out for 50 years or so, hopefully.
Getting an airdrop raided by bears can be a real issue. Clarke and Baldwin had to divert down the Machmell River because of that in the 80s.
Jan Palaty used to have a chunk of metal that had originally been a tuna can. A bear got to their airdrop in the Raccoon Pass area and chewed the whole can essentially flat.
I've seen a cache dug up by bears in the Tchaikazan., It popped all the propane cylinders but one. I think it liked the cold gas jetting out into its mouth.
When JC and JB did one of their big traverses near Terrace they came up with a coating for the cans that was (iirc) 1/3 flour, 1/3 cayenne pepper and 1/3 laundry soap. They mixed it together with water and then painted it on the cans. Apparently when they skiied up to one can there were wolverine tracks coming right up to it and then departing with twice the space between the tracks as on the approach