COOK IT OUTSIDE:
Spread 22 (+) hot coals in a flat layer underneath Dutch oven and add oil. When hot, brown brisket on all sides. Push brisket to one side in pot. Add onions and saute' until tender. Add 2 cups hot water, salt, pepper and hot sauce, if desired. Cover pot with lid,
Rearrange about 1/2 of the hot coals to make a cooking ring underneath Dutch oven; place remaining hot coals on lid. Simmer about 1 hour, stirring occasionally and rotating pot and lid several times during cooking. Adjust the number of coals on top and bottom as needed to maintain cooking temperature.
Pour reserved ketchup mixture over brisket. Cover and simmer slowly for 1 1/4 hours more or until meat is tender. Stir occasionally and add more water if necessary. Rotate pot and lid several times during cooking and replenish coals as needed for even heat. Let brisket stand at least 10 minutes before slicing across the grain.