I have never heard of anyone doing this. My personal opinion on prohormones is that they are not worth it at all. You get similar sides as being on, but you don't get nearly the gains. Add to that the fact that prohormones are nothing like they were a few years ago and how unregulated the supplement industry is = a recipe for disaster. You may lose your sex drive still, be out over 100$, and have nothing to show for.
I can tell you that I have come off before both on clomid/nolv and then with quitting cold turkey once when I was younger and I didn't lose my sex drive either time. So you may not have to worry about this. If you do though, there are other things to help with it and I think these would be a better use of your money if you are worried about your sex drive. This way you don't jack with your hormones anymore than you absolutely have to - my advice will always be to cycle off properly.