Rub all sides of the brisket with rub of choice. Set aside at room temperature for 2 hours. Prepare your smoker according to manufacturer’s directions. Arrange the brisket fat-side down on the grate and smoke for 3 to 4 hours, mopping with Fat Boy Vinegar Mop Sauce every hour. Set the temperature to 225 degrees and continue to cook the brisket, mopping occasionally with sauce, until an instant-read thermometer inserted in the thickest part of the meat reads 203 degrees (this will likely take 6 to 8 hours).
Foil the meat and let it rest for 30 minutes, preferably in an insulated container such as a cooler so the meat stays hot. Slice with a sharp knife across the grain into pencil-width slices. Serve and enjoy!