In a large heavy skillet, cook ground beef until evenly brown; drain well.
In a slow cooker, combine onion, bell pepper, celery, condensed gumbo soup, tomato paste and brown sugar. Stir in lemon juice, mustard, ketchup, barbeque sauce and vinegar. season with Worcestershire sauce, liquid smoke, parsley, black pepper and salt. Stir in browned beef.
Cover, and cook on low for 4 to 6 hours, stirring occasionally. Skim off excess fat.
