was it like a can of beans can or a can of coke? cos the coke cans are made of aluminium and are just as bad. if ur making a can pipe outa a coke can then do it only if ur really stuck cos burning the ink an shit isn't good fer yeh. just use the tinfoil (i know it's made outa aluminium but it's caled tinfoil over here)
get a socket off a wrench set and buy a packet of gauzes and gauze it up, it fits nice and snug in a bottle an if its too loose then wrap some selltape around it to make it a good fit (gauzes gotta be cheap in the USA like cos it's a pound fer 5 of them over here)