Create the dry rub by combining the salt, pepper, paprika, 21 Seasoning Salute, and garlic powder.
Rub the turkey generously with the spices. Apply the spices under the wings, skin, and every other area you can get to. Let the turkey "marinate" for 24 hours in the fridge.
Stuff the turkey with a whole onion and whole apples. This adds great flavor to the turkey. Then, place the turkey in the smoker with the breast facing up.
Smoke the turkey for 30-40 minute per pound at 225°F. The smoke time depends on the size of the turkey. The turkey is ready once the internal temperature of the meat reaches 165°F. Let the turkey rest and cool for 15-30 minute before slicing. Enjoy!