Step 1

Apply Butt Rub over entire roast. Place roast in a gallon size resealable bag and place in fridge overnight.

Step 2

Pull Roast out of fridge in the morning and lay on counter to come to room temperature.

Step 3

While roast is resting on counter, cut onion into 1/4" slices and place in single-layer on bottom of slow cooker. Set aside whatever doesn't fit.

Step 4

Place Roast on top of onions and lay remaining onions around roast.

Step 5

Sprinkle Worcestershire Sauce on top of Roast and set slow cooker on low for 8 hours.

Step 6

After 8 hours, remove bone from roast and discard. At this point, you should be able to easily shred the roast with a fork. Do this and mix with the onions and juices. Set slow cooker to warm until ready to eat.