Actually, this topic was discussed at great length in a thread in the old board, although the thread doesn't seem to have survived the transition to the new board.
The object in the jar is one of many objects claimed over the years to have been Rasputin's penis. All of them have turned out to be frauds so far. In fact, most of them were not even of human origin. See, for example,
http://www.themightyorgan.com/features_rasputin.html in which a sea cucumber was long believed to be Rasputin's penis.
An article with some clues to the legitimacy of the object is
http://www.iol.co.za/index.php?click_id=29...05A141&set_id=1 . This explains that the Sex Museum is actually attached to an impotence clinic, and contains objects designed to stimulate, as part of therapy, not necessarily to be real. For example, the doctor who runs the exhibt claims that the legend is true-- by just looking at the jar with the penis, impotence can be cured. At that point, all credibility about the object just became lost. It's starting to sound like just another con in the circus sideshow.
I suspect that this object, too, will turn out to be a tourist-trap hoax.