I was at the supermarket today when I saw the Becks and Heineken mini kegs. I was wondering would I be able to reuse theses for my homebrew? It seems like the only way to consume the Becks is threw the bottom spout. If that spout is opened can it be reused? As for the Heineken it seems to have its own C02 system in it. Anyone have any experiences with theses? Thanks in advance guys.