I've seen various products marketed for winterizing your pressure washer, but they're pretty expensive compared to a big jug of RV antifreeze that you could use to prep it for storage for the next decade of winters. I use the simple, patented set-up shown below consisting of a plastic pop bottle with the bottom cut off screwed into a short hose (the female x female appliance hose that I used required a male x male hose adapter). Anyways, I just fire up the pressure washer and give it an antifreeze IV and she's good for the winter, I thought this might help a couple of you who might have just got one this year, or never thought to do it before (freeze splits are no fun).
I removed the hose and drained it, there's no need to blast antifreeze through it when you can do that.