Soak mesquite wood chips in water for at least 30 minutes.
Preheat a smoker to 225-250 degrees.Sprinkle soaked mesquite chips over coals.
In a small bowl, combine garlic salt, onion powder, salt, pepper, and chili powder.
Rinse chicken and pat dry. Rub chicken with oil, and then sprinkle with garlic-salt mixture,.
Place chicken in smoker, and cook, with smoker lid closed, until meat thermometer inserted in the thickest portion registers 165 degrees, 3-4 hours. Remove from smoker, let chicken stand until cool enough to handle, approximately 30 minutes. Shred meat, discarding skin and bones. Serve with Alabama White Sauce.
Alabama White Sauce: Mix ingredients together in medium bowl. Cover, and refrigerate for up to 5 days.