Pat chicken drumsticks dry with paper towels. Trim excess skin (remove the skin if you like).
In a small bowl, combine seasoning mix.
Arrange chicken in a 6-quart slow cooker. Sprinkle seasoning over the drumsticks, tossing to coat. Brush 1 cup BBQ sauce onto the chicken.
Cover and cook on low heat for 5-6 hours or on high for 3-4 hours. Chicken is cooked through when the internal temperature reaches 160-165 degrees F.
Optional step: Turn the broiler on in your oven and place the oven rack in the top third of your oven. Line a large baking sheet with nonstick foil and arrange chicken skin side up on the baking sheet. Brush with more BBQ sauce and broil until the skin begins to brown and crisp up; about 3-5 (5-8) minutes.
Garnish with green onion if desired just before serving.
Feel free to use your favorite bbq sauce. I am partial to Sweet Baby Rays.