Heat a large stock pot or Dutch oven over a medium flame. Add the sausage and cook, stirring frequently, until browned, about 5 minutes. Use a slotted spoon to transfer to a paper towel-lined plate, and set aside.
Over medium heat, cook the chicken in the sausage drippings, stirring often, until browned, about 5 minutes. Transfer to the plate with sausage, and set aside.
Add enough oil to the drippings left in the Dutch oven to equal about 1/2 cup. Heat over medium heat, then very slowly whisk in the flour. Cook the flour in the oil, whisking constantly to avoid lumps, for 20-25 minutes, until the roux is a very deep, golden brown. Fold in the onion, bell pepper, and celery. Cook, stirring frequently, for 8-10 minutes, until tender. While stirring, pour in 2 quarts of hot water. Bring to a boil. Return the chicken to the pot, then stir in the okra, garlic, bay leaves, Worcestershire sauce, Creole seasoning, thyme, and hot sauce. Reduce heat to low, and simmer, stirring occasionally, for 1 hour. Use a slotted spoon to remove the chicken, and place on a cutting board. Set aside. Return the sausage to the pot, and add the sliced green onions. Cook over low heat for an additional 30 minutes.
When the chicken is cool enough to handle, remove and discard the bones, and cut the meat into strips. Stir the chicken back into the gumbo, and cook for an addtional 5 minutes. Remove and discard the bay leaves. Serve the gumbo hot, ladled over the cooked rice, and garnished with green onions.