Use a 6-quart slow cooker. Put the meat into your slow cooker. In a small bowl, combine the celery salt, garlic powder, pepper, steak sauce, and liquid smoke. Pour the mixture evenly over the top of the meat. Using kitchen tongs, flip the meat over a few times to disperse the sauce and coat all sides of the meat.
Cover and cook on low for 8 hours, or until the meat shreds easily between two forks. Serve over hot mashed potatoes or mashed cauliflower.