In 4 hours taste for flavor add seasons as needed. I usually add curry and garlic salt. If you like a spicy soup add a teaspoon of red pepper flakes.
Make a and serve with a pot of rice.
At about 8 hours oxtails should fall of the bone and to thicken sauce add some flour to the sauce.
Buy your oxtails from local meat market. Ask them to butcher them. When you get home rinse the meat and season with worchestshire and any of your favorite beef seasoning. Place in a plastic sealed bag and freeze until ready to cook.