You need a compressor to blow out the lines, and a bit of antifreeze for the drains. You can also put antifreeze in the freshwater lines if you want to, but we don't usually do that. I also put those moisture-absorbing beads out to try and prevent mildew (I just put a bucket of them in the kitchen sink and in the shower)
This guy gives a fairly comprehensive overview and is basically what I do.
https://youtu.be/DREjIdODAQE?si=VR9OyaQ6eWbe68B_
You need a compressor to blow out the lines, and a bit of antifreeze for the drains. You can also put antifreeze in the freshwater lines if you want to, but we don't usually do that. I also put those moisture-absorbing beads out to try and prevent mildew (I just put a bucket of them in the kitchen sink and in the shower)