Place 3- to 4-pound beef brisket on large piece of aluminum foil. Sprinkle generously with 1/4 cup of liquid smoke and 1/2 teaspoon each celery salt, onion salt and garlic salt. Wrap well and put into crockpot. Cover and cook on LOW for 8 to 12 hours or on HIGH for 4 to 6 hours.

Serve warm with juices over each slice. Or, refrigerate overnight and then slice thinly. Place in crockpot and pour 1 1/2 cups barbecue sauce over meat. Cook 2 to 3 hours on HIGH.