spray a 6 quart slow cooker bowl with nonstick cooking spray
in medium bowl, with wire whisk, stir together ketchup, mustard, vinegar, Worcestershire sauce, garlic, smoked paprika, and 1/8 teaspoons freshly ground black pepper. Transfer half of sauce to slow cooker bowl.
Sprinkle chicken with 1/2 teaspoons salt and 1/4 teaspoon freshly ground black pepper. Add to slow cooker bowl. Spoon remaining sauce over and around chicken to coat. Cover with lid and cook on high four hours or until chicken is no longer pink.
Transfer chicken to serving platter. Whisk cooking liquid until well mixed. Drizzle over chicken. Serve chicken with coleslaw and any remaining sauce. Serves four