The previous day, mix the ingredients for the dry rub together in a small bowl.
Gently dry the duck (including the inside) with paper towers and then, with the help of a sharp knife, make a series of long incisions in a criss-cross pattern on the skin (be careful to only pierce the skin and fat without cutting into the meat).
Pour half the dry rub into the duck's cavity and rub it in with your fingers as best as you can; then, sprinkle the rest of the dry rub over the skin and again, delicately rub it in with the tip of your fingers, so it gets into all the incisions that you just made.
Place the duck on a wire rack set over a roasting pan and place it in the refrigerator uncovered to air dry for 24 hours.
Preheat the oven to 325°F
Remove your duck from the fridge and flip it so it lays breast-side down on the wire rack; roast for 1 hour and 25 minutes, then remove the duck from the oven, insert a pair of kitchen tongs in its cavity and carefully flip the duck over.
Return the bird to the oven and continue cooking for about 45 minutes, or until a meat thermometer inserted into thickest part of a leg registers 165°F.
When the duck has reached this temperature, remove it from the oven one more time and increase the temperature 500°F (if your oven is equipped with a convection setting, now would be a good time to use it).
Whisk the orange juice, honey, coconut aminos, blackstrap molasses, toasted sesame oil and fish sauce together in a small bowl.
Carefully transfer the duck onto a baking dish, brush about half the glaze over the breast and legs and return the bird to the oven. Do a second basting after 5 minutes and then continue cooking until the skin becomes nice and crispy and a beautiful dark golden brown color, about 3 to 5 minutes.
Remove the duck from the oven and let it stand for 10 minutes, then carve and serve.