They inject them with a saline brine solution (yes, they did show this on one of the Travel Channel shows), and smoke them for I believe 6 or 7 hours. The saline injection is what helps keep them moist, as it draws the moisture into the turkey leg (and they are not emu, that is just one of those rumours, Disney has confirmed multiple times that they are turkey, I'm sure the FDA wouldn't look kindly on them selling fake food items).