Place beef bones in a large size slow cooker. Add salt, celery stalks, onion, bouquets garnis, pepper, carrots, parsley and garlic. Fill slow cooker within 2 inches of the top with hot water and cook for 6 hours, covered on high heat, stirring occasionally.
Add barley and cook for 2 more hours stirring occasionally or until meat can easily be removed from bones.
Remove and discard onion, bouquets garnis, celery, and parsley.
Transfer bones to a dish and remove meat from bones, being careful not to take off cartilage or gristle. Place meat back into soup, stir, and serve.