Combine beans and soda in a Dutch oven; add water to cover 2 inches above beans. Cover and bring to a boil. Reduce heat, and simmer 30 minutes. Drain and rinse beans well. Set aside.
Place salt pork in Dutch oven and cook until evenly browned; remove salt pork, reserving drippings. Saute onion and garlic in reserved drippings until tender. Add beans, salt pork, salt, and red pepper flakes; cover with water and cook over low heat for 2 hours or until beans are tender, stirring occasionally. Garnish with parsley.