Different coaches, different methods. My 93 Pace Arrow Diesel pusher just took opening the drain valves as well as ALL the faucets & such. I do pour the pink stuff down the traps, that's it.
This season & drained the system then pulled the Hot Rod out of the Hot Water Heater & it was dry! I think the water in the tank get's siphoned out thru a tube inside the H.W.H.
In 10 years of winter here in NH. NEVER had a freeze issue.
My 07 Discovery is a different story. Will be my 1st year winterizing it.
For all you diesel owners heading from the South up to COLD North should carry some anti-gelling diesel additive. Had a friend tat topped off down south, (summer Blend). During the trip north he got into some rather cold temps & the diesel started jelling! He dumped in two bottles of the anti-jelling & was able to make it w/o loosing his engine.
RM