I also have never heard of this being used on men. As others have stated above, it is generally used on female submissives and the body weight is supposed to be shifted slightly forward so that the clitoris is actually the first thing to come in contact with the horse/pony when the legs go.
Also, a side note, the Wooden Horse and Wooden pony are two different things, though similar. Much like an actual pony is a smaller version of a horse, a Wooden Pony is set lower so that you can get (kinda) relief by going to your tip toes. A Wooden Horse is taller, often to the point that the submissives feet cannot reach the ground at all. This same effect though, can be created with a pony by tying the subs feet up (to thighs, etc.) so that they cannot put them on the ground or relive the pressure in any way.
I'm not a guy so I wouldn't know for sure, but I'd imagine, like someone said that guys could actually cause physical, possibly irreparable damage, not just pain, to their genitals if they were to use this. In other words, what I'm saying is that in my opinion, I wouldn't have a guy do this as I think the possibility/risk of damage would be to high, but that's just my two cents. To each their own I say.
