Bob, you do understand that switching the valves' position from summer to winter isn't all there is to winterizing. All you have done for the work to get to those valves is to allow yourself to drain the hot water tank, so that when you put in the antifreeze you won't get any in the hot water heater itself. You will still have to drain that (use the pressure relief valve, then remove the element), and drain the rest of the water system and put antifreeze in it.
Since our 181 is nearly out of warranty, I'm going to take it to the dealer for the final warranty work and at the same time I'm going to have them winterize it, grease the axles, and do all the rest of the stuff that needs to be done annually. I'm also going to have them check everything over just as if it was just dropped off from the transporter, and fix anything that needs fixing. Yes, I'm going to pay some for the work, but having those service records will be important in a few years when we want to sell it for our FT coach.