I personally believe that hoping to use aluminum foil to boil water or cook food more than in a one time use is pretty much a false hope. Foil is usually included in our typical PSKs but has actual limited use, I believe. Holes develop very quickly from folding and refolding it. One of the most useful items we can have in a larger sized pouch size kit or even in the BOB should be something like a billy pot. A billy can be put directly on any kind of stove. It can be hung from a piece of wire over a fire to boil water or boil and cook food. It is a great way to collect water from most water sources. You can eat out of it and even dig with it. As far as hardware is concerned in the survival kit, a sturdy pot is almost as important as a good knife. Just my opinion!