Stir tomato sauce,
chiles, vinegar, honey, paprika, Worcestershire sauce, mustard and salt
in a 6-quart slow cooker until smooth.
Add chicken, onion and garlic; stir to combine.
Put lid on slow cooker and cook on low until chicken can be pulled apart, about 5 hours.
Transfer chicken to a cutting board and shred with a fork. Return chicken to sauce, stir well and serve.