Completely cover the beans with water and soak overnight.
Drain the beans and place in a large pot. Cover with fresh water and add the baking soda. Bring to a simmer and cook until tender, 40 to 45 minutes.
Preheat the grill.
Place the cooked beans with some of their cooking liquid into a large cast iron Dutch oven. Add the meat, ketchup, molasses, mustard, chili powder, garlic powder, vinegar, hot sauce and onions, and stir well. Add some fresh water to the pot to loosen up the mixture. Cover with a heavy lid and place on the grill over indirect heat. Cook, stirring occasionally and adding water as needed, for 3 to 4 hours.
Recipe courtesy of G Bar M Ranch, Clyde Park, MT