I can honestly say that I've never purged. The reason I can say that is that my societal training was severe enough that, even though I knew I had a "special interest" in things feminine, I never acquired anything to purge.
Obviously, having lived most of my life with the idea but not the actions of crossdressing I could probably go back to that status if it were absolutely necessary. It would probably take a considerable toll on me mentally, though, and that could lead to an outcome that is much less desirable than continued CDing.