[flybouy]

I use compressed air and antifreeze. Blowing out the water lines doesn't remove the water from the pump. I blow the lines out first for 2 reasons, 1 to remove water and 2 to reduce the possibility of water diluting the antifreeze. Run the "pink stuff" through the pump and all valves then pour some in each drain with extra in the toilet with the drain closed. It takes about 3 gallons to winterize my unit.
Where I live the Temps can vary by a large margin. Around 40 yrs ago the Chesapeake Bay froze over and I was able to drive my '72 Grand Torino miles out over the water. Other years I've washed vehicles in the driveway in Jan & Feb. So for my money I'll use the antifreeze and error on the safe side.