Shimazaki Dry Shake is the best choice available for a reconditioner. Not only is it a desiccant but a water repellent powder as well. This handles soaked and slimed flies on the spot, even with the tippet still attached. Shake your flies in the powder a few times and they'll be good as new, ready to go. Shimazaki even works on materials that have a tendency to clump with other floatants.
Use Dry Shake Primer prior to first use to extend the life of the treatment
Remove surplus water before use to avoid wasting powder