Place beans in a large stockpot or Dutch oven; add enough water to cover the beans by 2 inches. Cover the pot and soak the beans overnight.
Heat olive oil in a large Dutch oven or stockpot over medium-high heat. Add the sausage and cook, stirring, until nicely browned (about 3-5 minutes). Remove sausage to a plate and set aside for later.
Add onion, bell pepper and celery to the pot. Cook, stirring, until tender (about 3-5 minutes). Add the garlic, bay leaf, thyme and oregano; cook for 1 more minute.
Stir in the ham hock, drained beans, Cajun seasoning, and enough water to cover by 2 inches. Bring to a boil, then reduce the heat to a low simmer.
Gently simmer the pot, uncovered, for 2 hours, or until the beans are very tender, stirring occasionally. Add more water if the mixture gets too thick. Use a spoon or a potato masher, if desired, to mash some of the beans to give the mixture a creamier consistency. Remove the ham hock and bay leaf. If you’re using a meaty ham hock, you can pull off any good meat and return it to the pot (this is optional).
Stir in the vinegar and browned sausage; season with salt, pepper and hot sauce, to taste. Simmer for about 5-10 more minutes, just until the sausage is heated through.
Serve over rice; garnish with fresh parsley.