The more water (to a point) means more lube and less aggressive and less blade-hone contact. As you use less water the lube decreases and the blade contact becomes more aggressive and requires more finesse. Of course this can change with the stone but it's a pretty good general principal.You can experiment with different liquids (theoretically) for differing results.

For a real treat try some heavy water. Too bad the National Lab frowns on stealing it.

Har har.