Shimazaki Dry Shake is the best dry fly reconditioner on the market. This is both a desiccant and water-repellent powder in one. This allows you to recondition soaked or slime covered flies on the spot. The bottle is designed to treat the fly with the tippet still attached.
Simply place the fly into the bottle and gently Hold the lid closed. Turn the bottle upside down and shake a few times. False casting will remove any excess powder, and your fly will float as if it were new again. Shimazaki works wonders on CDC and other materials that tend to clump with other floatants. The DUN color works best on dark colored flies