Rest time: 10 minutes
Remove the outer membrane from the ribs- it is always easier to use a butter knife and a paper towel to help grip the membrane.
Rub olive oil all over the slab of ribs, then slather in rub so no part is exposed without rub.
Place ribs in smoker with the meaty side up (you may need to cut in half to fit the entire slab) and smoke for 3 hours at 225 degrees, remembering to set a timer for 3 hours.
After 3 hours, take out two large pieces of foil long enough to wrap the ribs, double them up and place the ribs on top. Add the apple juice on the bottom of the foil and the butter pats on the top of the ribs. Wrap up the foil packet tightly and place back in the foil for another 2 hours at 225. Set your timer for another 2 hours.
Remove your ribs from the foil packet and place back on the smoker grates, meaty side up. Generously cover the meaty side of the ribs with BBQ sauce. At this point, you can crank your smoker up to 300 (you are still cooking on indirect though) degrees- you are letting the bbq sauce set on the grill. Smoke for an additional one hour- set your timer.