I am using Tiemco Dry magic and treat my dry with that before it first gets wet. This stuff isn't cheap but it works well on any dry I've used it on, including CDC. Once I get some fish on it or if it starts to sink, I recondition it with some sort of shake n float. Right now I have Orvis Hy-Flote Shake n Flote because that's what the fly shop had on hand. I'm not quite as picky with this stuff as I am getting the Dry Magic. That stuff is the bomb.
Fly-Fishing Floatant / Hy-Flote Shake-N-Flote Renew -- Orvis
Once a fly gets beat up pretty good, hang it on your fly patch or put it back in your box to dry out and tie on another.