RE: Water Wetter
I believe the tech term for this type of additive is 'surficant'. 
Breaks the surface tension in water so that it flows easier and makes
better contact with the inside surfaces of the engine and cooling
system.  This allows more efficient heat transfer, from the engine and
out the radiator.
A similiar product was demonstrated for use by fire fighters, makes
the water 'slippery' and allows the same pump/hose combination to
shoot water a greater distance.  I don't know it it is actually used
by firefighers, just remember seeing video of an impressive
demonstration.  I have to wonder if a few drops of tide a few pinches
of TSP might accomplish the same thing.