Marinate beef brisket in Worcestershire Sauce, Salt, Pepper & Garlic Salt for 12 or more hours. (I use enough Worcestershire sauce to cover half the brisket & then turn it over half way thru the marinating process.)
After marinating drain the liquid, cover the pan with aluminum foil and cook on low (180-200) overnight.
Discard the liquid, let cool. Cover with aluminum foil and refrigerate.
About an hour & a half before serving, thinly slice the brisket on the bias. Place in pan & cover with your favorite BBQ sauce; then generously cover the sauce with brown sugar. Cover the pan with aluminum foil & bake at 350 for 1 hour or less.