Just to be pedantic, as this is the Internet after all :-), distilled water is a pretty good insulator, but not a "perfect" one. Neutral (pH 7.0) water always has a very small amount of the molecules disassociated into H+ and OH- ions. However, as others have stated, the effective value of the water resistor, compared to the load resistor(s), will be negligible.
- Distilled water (was re: Model 152 PSU dummy loads) Craig Ruff