Barbecued Brisket of Beef

1 (10 pound) fresh brisket
3 tablespoons liquid smoke
1/2 teaspoon garlic salt
1/2 teaspoon onion salt
1/2 teaspoon celery salt
3 teaspoons Worcestershire sauce
1 cup barbecue sauce

Mix liquid smoke, garlic salt, onion salt, celery salt and Worcestershire sauce. Sprinkle brisket with pepper. Cover both sides of meat with sauce in a baking dish. Cover tightly with foil and place in refrigerator overnight.

The next day, bake (covered) at 300 degrees F for 5 hours. Add barbecue sauce after 4 hours and leave uncovered from then on.

Slice and serve.