ok, so i'm going to a party in a couple of weeks. this party involves a white elephant gift exchange for which you bring a unique vessel out of which to drink alcohol. so, in my infinite cheepness, i came across an expired fire extinguisher. i removed the top, its threaded btw, and dumped out the powder. the msds on the powder let me know that its non-toxic so whoever drinks out of it will, at least, not die. i cleaned it out, but the inside of the aluminum bottle is not polished or finished or anything. i found this out when i stuck my finger inside and wiped the edge and it came out black (no dirty vag jokes, please). so, it appears that the inside is not treated and i think, i good taste, i need to coat the inside with something. i've found that a lot of water bottle co's line their Al bottles with a plastic epoxy. does anyone know where i can get this or a food grade paint to coat the inside? i figures at the very least one could shake it up if it had beer in it for pressure or i could bring a pancake air compressor if needed, to aid in drinking. thoughts?