Drained antifreeze after winterizing; ok or not okay?

I put a water heater bypass on my Water Filter. These take up very little room. They are made by camco and come in different lengths (8", 12")





Then, if you tank is visible, I would have taken off the sump and stuck it into each bottle to winterize instead of filling the tank. Or, you could have gotten one of these gizmos installed at the pump.