40 years of winterizing the same RV. I've never used any pink stuff RV antifreeze. I blow the lines, don't even add anything to the traps. Traps seem to have a sufficient width compared to the height that they don't break when they freeze, plus the traps often have detergent in them - which lowers the freezing point. In the forty years, I've twice had pipes burst from insufficient blowing out. Once was due to a low point I didn't know about. Once was just due to not blowing long enough and leaving water in the tubing.
I know my RV well enough now that I just don't need the antifreeze. If I had one I didn't know that well, I'd probably use antifreeze. My RV is so old, it uses copper tubing, which results in some slight corrosion from the air. That corrosion can release and clog filters when I refill, so I pump a fair amount of water through when I refill in the spring with the faucet screens removed.
I always disconnect the pump and turn it upside down and left/right to ensure it's completely empty.
