We know it sounds wrong, especially considering how sacred the Thanksgiving bird is. Let me guess, you only eat roast turkey once a year? Us too. But we're talking about a pickle brine, not stuffing a turkey with pickles. Brines are super salty in nature, so pickle juice makes sense.
Check out the video recipe here: https://www.delish.com/holiday-recipes/thanksgiving/videos/a56451/pickle-brined-turkey-video/