Make the mustard barbecue sauce: Combine the Worcestershire sauce, apple cider vinegar, white vinegar, garlic, cumin, pepper, sugar and salt in a medium saucepan and bring to a simmer over medium heat. Simmer, stirring frequently, until the spices have hydrated and the sugar has melted, 2 to 3 minutes.

Add the mustard and hot sauce to the saucepan and stir to combine.

Turn off the stove. Blend the ingredients in the saucepan with an immersion blender while slowly drizzling in the oil. Store in an airtight container in the pantry for up to 1 week.

Make the chicken: In a large mixing bowl, whisk together the garlic, white pepper, hot sauce, pickle brine, salt and oregano. Add 1 quart of water and whisk until the salt dissolves. Set aside while you prepare the chicken.

Place the chicken in a resealable plastic bag and add the brine. Remove as much air as possible from the bag and close it. Place the bag on a sheet pan (to catch any brine that might leak) and refrigerate overnight.

The next day, remove the chicken from the bag and discard the brine. Pat the chicken dry and sprinkle it lightly with salt and pepper. The chicken is already seasoned internally with brine, so the pepper is mostly for appearance, and the bit of extra salt is delicious on the skin. Let the skin dry even more at room temperature as you prepare the smoker/grill.

Prepare a smoker or grill to cook between 350 F and 375 F with coals or burners only turned on low, on one side.

Cook the chicken bone-side down on the grate, offset from the heat or coals for 30 to 40 minutes, or until the skin has dried out significantly. Brush the skin with the barbecue sauce and turn over to skin side down directly over the coals or heat to sear and char the skin lightly for 1 to 2 minutes. Flip the chicken back over to bone side down offset from the heat and brush again with barbecue sauce. Cook the chicken for 70 to 90 minutes total, or until it reaches an internal temperature of 180 F in the deepest part of the breast and thigh.

Remove the chicken from the grill, brush it once more with barbecue sauce and then wrap it tightly in foil to rest for 10 to 25 minutes. As the chicken rests, the skin will soften, creating a texture similar to rotisserie chicken skin. Carve the chicken and serve.