J,
No "wisdom", just what I do.
As I frequently camp (and then return home) in sub-freezing temps though out the winter, I use the "dry method".
Drain everything, blow air through the lines, and dump a little anti-freeze in the sink and tub traps.
No "fancy" fitting, just a device that allows my air hose to connect to the pressurized water inlet which I suspect you can get it at RV stores.
Takes about a hour which includes dumping the tanks (as long as the dump valves aren't frozen....)
I suspect you will find many others who prefer the "wet method".
Safe travels,
Steve