In a large Dutch oven, place the beans and 1 tablespoon of salt. Fill with water to cover the beans. Cover and soak overnight or bring to a boil for 2 minutes, then remove from heat and let stand for 1 hour.
Drain and rinse the beans. Set them aside.
In the Dutch oven over medium heat, heat 1 tablespoon of oil. Add sausage and cook until browned, 5 to 7 minutes. Add remaining oil, onion, bell pepper, and celery. Cook until vegetables are soft, 5 to 7 minutes. Stir in garlic, thyme, black pepper, sage, cayenne, and remaining salt. Cook until fragrant, 30 seconds to 1 minute.
Stir in chicken broth, ham hock, bay leaves, and drained beans. Add enough water to cover beans by 2 inches, 2 to 4 cups. Bring to a boil, cover, reduce heat to low, and cook until beans are tender, 1 hour and 15 minutes to 2 hours, checking after 1 hour and 15 minutes.
Remove lid and continue to cook over medium-low heat, stirring frequently, until liquid is reduced and creamy, 25 to 30 minutes. Discard bay leaves and stir in vinegar. Adjust seasoning to taste.
Serve the beans over hot cooked rice with hot sauce and sliced green onion, if desired.