The obvious way is to just use the pink stuff and flush it out when you can use the systems again in warmer areas. That is a pain and takes a lot of flushing to get it out of the water system. No big deal if you are heading home, but if it going out or midtrip, you have to find a full service campground to do it. The good part is that when traveling, the inside stuff will stay above freezing, so the critical pump areas are pretty safe.
We have always intended to use an air blowout before leaving as it is very thorough on most of the system, and does a very safe job on the underbody areas. We have an onboard compressor for the airbags and tire lifter, so using that makes sense for mid and going home winterizing. Biggest issue was controlling it so we don't overpressure the plumbing as there is no settable regulator on it, or tank pressure gauge. I tried doing a timing of opening and closing faucets, but the pressure builds way fast with everything closed, so nearly impossible to keep up.
Our air port is a Schrader valve, which our air hose hooks onto, and the hose has a Schrader female end for tires. A Schrader on the blowout fitting would work, but require a gauge and checkvalve. I then decided to try to make an airfeed to the blowout that had a manual valve, gauge, and checkvalve built in. As it turns out, the cheapo tire fill guns have all of that already. They also have a quick clamp on the output hose, with the inlet an air QD. I bought two of them, and managed to remove the output hose from one and adapt it to the inlet of the second one. That way I had a hose with a quick clamp Schrader head on both inlet and outlet, so it just clips to van air port, and the blowout fitting with a Schrader valve on it, and stay connected at both ends.
You can either leave a faucet open and let the pressure drop as low as it will go, which is pretty low if the strainer is off, or have everything off and pull the handle to get to 40ish psi, and release it so it holds. Then you can open an outlet and get that nice initial blast, which seems to work better. All in all, it works really well, without overpressuring or having the pump run continuously. It does seem to be doing an adequate job of getting rid of the water in the system, especially in the vulnerable areas. Of course, I still prefer the big home compressor, where I can just set the pressure and let it go. It keeps up easily and will hold whatever pressure is set, so the blowout is very quick and thorough.