I just ordered some rubs from BP. Can anyone tell me the proper way to use a finishing rub? Is it used after the cook as a final seasoning or for the last part of the cooking time?
"Proper" use would I my opinion depend on the meat that you are working with. It goes with "layers of flavor" theory. You want to layer on the rubs and sauces so that they create a complimentary flavorful outer crust.
On pork, you can mix in a finishing rub to your pulled pork then add some sauce/jus. You could also hit your money muscle bark with a bit of it. Key is to not over do it. You are just adding a re-fresh of flavor that will supposedly "pop" when you take a bite.
Chicken and ribs would be sort of the same, an additional layer of flavor added at near the end of the cook or afterwards.
You can also grind regular rubs to make a more powdered version of the original rub you used.
depending on the cut of meat, and it's intended purpose... I use Money on my ribs, with Sweet money in the wrap, and happy ending on before I sauce glaze finish.... But for something like brisket, I put a grind on Double Secret Steak rub and dust the slices with it after a run through the aujus. Gives it just the right pop. I would just add another layer when I wrap if I was cooking for myself.