You need to watch out. A cousin of mine tried to brine a Swift’s Butterball and miserably failed. Turned out that Swifts injects shortening that defeats much of the brining process and makes it unnecesary.
Exactly right. use a FRESH turkey, not one that has already been injected like a Butterball.
Here is a recipe I have been using for years and it seems my wifes family wants Thnaksgiving at our house every year as a result........
http://articles.sfgate.com/2004-11-17/food/17454587_1_brined-turkey-big-bird-larger-bird/2