[Mark7]

I use 2 gallons including all faucets, outside shower, and W/D. I collect what comes out of each faucet in a cup and run it thru again until I am sure all of the water lines are full.

I do blow it out ahead of time... I always put the water heater in bypass, remove the anode rod (drain) and then hook up the air. It is amazing how fast the water exits the water heater with 45 PSI pushing it. I have it in my head I blow out a lot more sediment that way, rather than just letting it drip. I leave the drain out and put a piece of cotton clothes line rope in the drain hole to wick out any remaining water. Concrete will be wet under that rope for a week or so afterward as it wicks out the bottom of the tank.

I only blow out the black tank flusher and have never had an issue... again with 45 PSI.

Whatever antifreeze remains goes in all the traps.

20 years of this method and never a problem.