1.Combine thyme, paprika, pepper, salt, onion powder, garlic powder, cayenne, and cumin in a small bowl; set aside. Rub brisket all over with liquid smoke, then rub with spice mixture.
2.Pour Worcestershire and barbeque sauces into a slow cooker; place beef on top. Cover and cook on Low 8 to 10 hours, until fork tender.