Probably one heck of a trade item. Thinking of 1 Second After where every virile woman under the sun was getting knocked up because of no BC. Have to store them in a very cool place and uhhhh... "rotate your stock".
as stated, they are issued in survival kits for a reason. You can use them for so many reasons. Collect water, in Vietnam they were used to keep water out of barrels. Just like so many items, the number of uses is only limited by your imagination.
They're no longer part of Army Aviation Survival Kits; haven't been since 1973 anyway. We used purpose-made water bags (which had a higher capacity) and with the advent of the hydration systems, just about everyone carries their own water in some fashion.