Water pumps these days use a lubed-for-life bearing with an integral ceramic seal that is pressed into the waterpump housing opening from which the pulley shaft extends. Coolant lubricity properties are a non-issue since the water pump bearing is no longer exposed to coolant. Concern yourself about potential cavitation damage and internal cooling system passage corrosion issues and choose your coolant according to your specific engine manufacturer's requirements. If in doubt, contact your engine manufacturer's rep for advice about the suitability of using a wetting agent. Ethylene glycol, the main ingredient (~93%) in most commercial antifreeze concentrates, is to some extent a wetting agent anyway, since dilute coolant tends to sheet rather than bead when applied to a clean, dry surface.
