Bring a large pot of water to a rolling boil. Boil the beans for 15 minutes. Drain and rinse.
Optional: heat the olive oil in a large skillet over medium heat. Add the onion, celery, and pepper. Sauté for 5-7 minutes, or until the vegetables are tender and the onion is gently browning. Add these ingredients to the slow cooker.
Add all remaining ingredients except for rice and vinegar to the slow cooker. If you don't choose to sauté the vegetables, you can skip the olive oil and dump everything but the rice and vinegar into the slow cooker now!
Cook the ingredients on low for 6 hours or high for 3 hours. Add the rice. Continue cooking for 2 more hours on low or 1 hour on high (1 1/2 hours if you use brown rice instead of white). Remove the bay leaves. Stir in the vinegar and add additional salt as needed. Serve, with plenty of hot sauce and chopped green onions if desired.