About the can....
Cook's Illustrated/America's Test Kitchen answered the can enamel question some years ago, and their research said that the liquid kept the can cool enough so that no chemicals from the can went into the chicken. Just me, but I would wash the can with dish liquid and water, rinse well, and dry with a cloth before proceeding.
Norpro brand makes a vertical roaster that ATK likes. One pours the beer or other liquid into the center of the roaster. I got the store brand roaster from Sur La Table.
If you're having me over, or someone else who does not drink alcoholic beverages, canned lemonade will also work. Water does nothing, nothing for the flavor of the chicken, so beer or lemonade is the ticket.
Lawrence/Maytagbear