|Remove skin from chicken. Rinse chicken; pat dry. Spray inside of crockpot with nonstick coating. Arrange the chicken, meaty sides up, in crockpot. Brush with milk.
In small bowl, mix onion powder, thyme, garlic salt, white pepper and black pepper. Sprinkle over chicken. Cover and cook on LOW for 8 to 10 hours or on HIGH for 4 to 5 hours until the chicken is tender and no longer pink.