I have been using distilled water for years, but only for the developer and Photo-Flo. Since I move from time to time, using distilled water in the developer prevents me from having to do new developer time tests every time I change water supplies. I have my own distiller, but even if I had to buy it, I would do so for the developer only (film, by the way, NOT paper!).

And, as others have already pointed out, distilled water with Photo-Flo or other wetting agent will guarantee the cleanest possible drying process.