Beef Brisket

We've been making this brisket recipe for as along as I can remember.

1 (5lb) beef brisket, trimmed of excess fat (sometimes I leave the fat on for flavor and trim it before serving)
2 tsp. garlic salt
2 tsp. onion salt
2 tsp. celery salt
1 small onion, minced
5 Tbsp. Worcestershire Sauce
1 (2 1/2 oz.) liquid smoke (some people further north might have a hard time finding this)
1/4 tsp. coarsely ground pepper

Place brisket in pan (9x13 baking dish works well); sprinkle remaining ingredients except Worcestershire sauce and pepper. Cover with foil and refrigerate overnight. Next day, sprinkle Worcestershire sauce and pepper. Preheat oven to 275. Bake for 6 hours. Remove from sauce and shred or slice meat.