Place beans in a large bowl and add 12 cups of water to cover. Leave uncovered on the counter overnight.
Discard soaking water and rinse beans with fresh water. Drain well and place in crockpot.
In a large skillet, heat oil over medium-high heat. Add Andouille sausage and cook until browned, 8 to 10 minutes. Remove sausage with a slotted spoon and place in crockpot.
Add onion to skillet and cook until softened and beginning to brown, about 7 to 9 minutes.
Add celery and bell peppers and cook for about 3 minutes.
Add garlic and cook one more minute. Transfer mixture to the crockpot.
Add about 1/2 cup of the chicken broth to the skillet and heat over medium heat. Use a wooden spoon to scrape up all the browned bits from the bottom of the skillet. Transfer to crockpot along with remaining chicken broth.
Add remaining ingredients to crockpot and give everything a stir. Cover and cook on HIGH for 3 to 4 hours, until beans are softened.
Add parsley and green onion to red bean mixture and serve over rice.