Place meat in a 5-qt. slow cooker. Add onions and celery. In a bowl, combine the ketchup, water, lemon juice, Worcestershire sauce, brown sugar, vinegar, salt, mustard, paprika, chili powder, pepper and hot pepper sauce. Pour over meat. , Cover and cook on high for 6-8 hours. Remove meat; cool slightly. Shred meat with 2 forks. Return to the slow cooker and heat through. Serve on rolls.