Er...I'd always heard the Jade Gate referred to a part of a woman's anatomy--but perhaps you know more than the wisest of men since the location you sited is "dunhung. :-)
Ah, the old jade gate/ turtle head reference eh?
I kind of like the grotto of aphrodite/rampant steaming engine of manhood victorian phrase myself.
Wonder if this is some precursor to the "Got a wild hare
up yo butt?" reference. If so no wonder it has such a conotation. Hares are a lot bigger than gerbils eh?