Winterization Air vs Chemicals...... Your 2 cents please

We are in Alberta, Canada and it gets very cold in the winter so we use both air and antifreeze but some just use antifreeze. Just do not want to take the chance that some water may be in a low section of the water line and freeze causing many dollars for repair. We make sure outside shower and all water outlets are cleared of water and have never had a problem even at 40 below. When you see pink coming out of the tap you are good, usually 2 people to do the job right.
Good luck