Winterizing Process

I personally have never used anti-freeze but I would think that method would be the more sure proof system. I have always felt confident that I have blown all the water from my lines. I usually leave the air on for a few minutes. When our son played college baseball we used our trailer for a motel. The college season for him started in March (earlier if you counted the trip to Florida). March in northern Indiana still can get well below freezing (albeit not like the Western mountains) so I found myself blowing out the lines and draining the water heater very frequently. I would not have wanted to pump anti-freeze into the lines on a weekly basis. But maybe it's less than a chore that I imagine.