Rainex sounds interesting however I wonder if it wouldn't be similar to wax? From my days of racing performance sailing dinghies we stayed away from wax as it causes water to bead up, this actually slows the boat down - plus it makes it really hard to right after a capsize.

Some of the hotdogs were experimenting with long string polymers, we just used rubbing compound making sure it was applied only in the direction of water flow.