Holson,
What I mean by appropriate is that you should add the recommended amount of water wetter for best performance.
This is NOT one of those things where 'If some is Good, then more must be Better'.
The water wetter is simply reducing surface tension (surfactant). The water wetter liquid itself is NOT what is giving the improved cooling abilitiy...the actual WATER is still doing that. It's just that the water wetter allows the WATER to do it's job a little better.
That reminds me....I need to head on down to PepBoys and pick up some more DFC and a bottle of Water Wetter myself