- Mix celery salt, black pepper, salt, garlic salt, and onion salt in a small bowl; add Worcestershire sauce. Spread mixture over beef brisket; transfer to a slow cooker.
- Cook on Low until beef is tender, about 8 hours.
- Transfer beef to a cutting board; shred into small pieces using 2 forks.
- Measure 1/2 cup cooking liquid from the slow cooker into a saucepan. Mix in Russian dressing and barbeque sauce; bring to a boil.
- Combine shredded beef and sauce mixture in the slow cooker. Cook on Low until flavors combine, about 1 hour.