Rinse beans, and place in a bowl with water to cover by 2 inches. Let stand 8 hours or overnight. Drain.
Heat oil in a Dutch oven over medium-high. Add andouille; cook, stirring occasionally, until browned, about 3 minutes. Using a slotted spoon, transfer andouille to a bowl, reserving drippings in pan. Add bell pepper, onion, celery, chopped green onions, garlic, thyme, sage, and red pepper to pan; cook, stirring occasionally, until softened and browned, about 7 minutes. Add beans, 6 cups water, stock, salt, and bay leaf; bring to a boil. Reduce heat to medium, and simmer, uncovered, until beans are mostly tender, about 1 1/2 hours.
Stir in andouille and rice; cover and cook 1 hour or until rice is tender. Remove from heat; discard bay leaf. Stir in chopped parsley. Top with parsley leaves and serve with hot sauce, if desired.