Well, I will give 3 ways to winterize
First winter I used pink stuff.. Come spring I had to get rid of it all. What a mess.. I finally got the tank cleaned out and the lines cleaned out.
Next 3: The Dry method, Blew the lines out (holding to 45-50 PSI) like 10 times waiting a few minutes between blows with all valves (Save to water heater valves) open including low point drains (and the 3rd water heater (bypass) was open) .. Pink in drain traps and toilets, No problems come spring, Nothing to "pump out".
Now I use the SOUTH method.. But then I full time in the RV, no house no more. so I just head SOUTH in the winter.