Coat the steak liberally with salt and let it dry brine in the refrigerator overnight (8 hrs minimum)
Rinse the salt from the steak and pat dry with paper towels.
Season the steak with the steak rub.
Smoke the steak at 225F with hickory for an hour or until the steak reaches an internal temperature of 130F.
Remove the steak from the smoker and sear for one minute per side. You can use a hot grill or a cast iron pan on your stove.
Baste the steak with melted butter, slice thin and serve.
Notes
You will often find Top Round steak being sold as "London Broil". This affordable cut of beef is not as tender as most steaks but it will treat you right as long as you go Low and Slow.