Bear, the answer is "yes". All of the ways you have described will work fine. How you like the end product depends on your personal taste. I like to use mustard but if you put mustard on first, ain't much rub going to get through. I sprinkle with my favorite rub (Dizzy Pig is right up there) and then I rub the yellow stuff allover. A bit of the rub will come off but that's ok. I have done them without mustard and without rub and even did one without anything. I prefer to use a rub that I can rub well into the meat. I have brined them before and I have injected them but a basic rub with mustard on top is pretty hard to beat. Could you mix the rub with the mustard? Yes, but I really like to rub the rub into the meat first.
