I have dedicated smokers, but I watched an ATK or Cook's Country episode where they did a 12 pound whole packer beef brisket on a Weber 22", charcoal grill using the snake method of placing the charcoal. There were two layers of 58 charcoal briquets placed around the outer edge of the grill on top of the fire grate, almost a complete circle with about a 10" gap between beginning and end, with unsoaked wood chunks about every 5-6 inches on top of the snake for smoke. A foil pan was placed in the center of the grill on the fire grate, in the middle of the snake and filled with water for moisture. The snake was lit at one end with 10 coals started in a chimney. The cooking grate was placed on the grill and the brisket was placed in the center, trimmed fat cap down. A temperature probe was placed in the brisket in the center of the point/deckle. Bottom vent and lid vent fully open. The brisket was cooked to an internal temp of 170F, removed and wrapped in foil. There were still some unlit coals in the snake and the gap between beginning and end was filled with unlit briquets to complete the circle. The cooking grate was replaced and the wrapped brisket was placed back in the same position and the probe was placed back in the same position. The lid was put back on and the brisket was cooked to an internal temp of 205F. The brisket was then removed from the grill and placed inside a dry cooler, still wrapped, for 3 hours. When served the internal temp was 160F. The brisket was prepped by trimming a lot of fat, rubbed with a kosher salt and fresh ground black pepper mix, loosely covered with plastic wrap (basically a tent) and did an over nighter in the fridge.