Winterizing- rv antifreeze vs. blowing out lines

I pump the pink stuff in all lines including my outside shower , this gets all lines including the pump. The only thing that does not get is my black tank flush , for that I use an air compressor and put one of those .50 cent adaptors on , a few seconds of air into the black tank and we are good to go.

It's always a sad day when this topic come up.... :(