What should I do to winterize the dishwasher if it won't be used during freezing temperatures?

Turn off the water supply, then pour one gallon of nontoxic RV or Marine water system antifreeze into the bottom of the tub. Set any wash cycle, close the door, and allow the dishwasher to run for 3 minutes to distribute the antifreeze throughout the water system. Before using the unit again, fill both detergent cups with dishwasher detergent and run a complete Normal cycle without dishes to remove the antifreeze. (Page 11)