I've only winterized once, but everything was fine in the spring using just the blowout method. I didn't follow a specific procedure, but I ran the air for quite a while and was thorough about individually opening and closing the various valves and faucets--as well as running the pump--to ensure that the pressurized air got everywhere. I think I also raised and lowered the tongue a few times for good measure, and left all the drains open when I was done.