Weep hole is in the bottom of the pump ,and not on the top .I would think its impossible to oil the bearings in the water pumps. Reason is the bearings are sealed .. Once seals wear then water comes frrom the weep hole.Its the shaft that holds the bearing that goes rusty ,it then wears the seal till coolant leaks out. Years back old timers used to put a little suds oil in the radiator to help lubricate the bearings inside the pump.