I have been winterizing for years without any antifreeze by using an air compressor. I made an adapter (based on what I saw pool contractors use to blow out the lines in a swimming pool) that ends with a male 3/4 inch hose fitting that I screw into my dock pressure water inlet in the cockpit. Then I pressurize the whole system right from the cockpit and go below and open each faucet, hot and cold without having to move the compressor at all. As Larry does, I start by draining the water tanks and the hot water heater. Works great, no mess, no foul taste in the tanks from the pink stuff.