Rinse and drain the beans. In a 4-to-6-quart Dutch oven combine beans and 8 cups water. Bring to boiling; reduce heat. Simmer fro 2 minutes. Remove from heat. Cover and let stand for 1 hour. (Or place beans and water in Dutch oven. Cover and let soak in a cool place for 6 to 8 hours or overnight.) Drain and rinse beans.
In the Dutch oven cook bacon and onions until bacon is crisp. Drain off fat. Add the beans and 6 cups fresh water to Dutch oven. Bring to boiling; reduce heat. Simmer, covered for 1 1/4 to 1 1/2 hours or until beans are tender, stirring occasionally.
Stir in the catsup, molasses, mustard, oregano, salt, and pepper. Bring to boiling; reduce heat. Simmer, uncovered for 30 to 45 minutes more or until desired consistency, stirring occasionally. Makes 10 (2/3 cup) to 12 servings.
NOTE: 25 servings: Prepare as above, doubling amounts of all ingredients. Soak beans in 12 cups water in an 8-to-10-quart pot. Cook half the onions and bacon at a time. Cook the beans as above, except stir in 10 cups of water in Step 2. Cook, uncovered, in Step 3 for 1 to 1 1/4 hours, stirring frequently.
NOTE: 50 servings: Prepare the 25-serving recipe twice (do not double the recipe). Prepare two smaller batches, as there's less danger of burning beans at the bottom of the pot.
Tip: To reheat, cook over medium low heat, stirring occasionally, until bubbling, about 30 minutes.