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. 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.