Windshield washer OK for winterizing waterlines?

Windshield washer fluid is NOT acceptable to winterize your water lines. Do not use it.

The stuff to use is non-toxic RV antifreeze. Use nothing else, except air. Blow out the lines with a low pressure air compressor (20 psi is plenty, but under no circumstances more than about 50 psi) to remove as much water as possible, then fill those lines with the pink RV antifreeze. Though more expensive than windshield washer fluid, it is a LOT cheaper than a liver transplant. Trust me on that one.