Combine, garlic, basil, oregano, parsley and olive oil, then blend in a food processor or blender until smooth.
Spread evenly over all the surfaces of the meat and rub into meat until the meat seems to absorb any dripping, but is still moist. Coat the entire piece of prime rib in rock salt to create a crust.
Insert a digital meat thermometer into center of prime rib and place in the smoker at 225-230 degrees until the meat thermometer reads 110 degrees. Depending on the size of meat, this could take 4 to 6 hours. It is more important to watch the temperature than the clock.
Remove the prime rib from the smoker and carefully brush the salt crust away.
Allow the meat to stand uncut until the temperature stops rising. Around 20 minutes