"Walks Through Walls" is still exploring! I wanted a new way to the old Waterfall and "Bengal Tiger Cave" in the Zul'Gurub instance, and with some looking around I found it.
Thanks to Dellion for showing me the fast way out of ZG. Thanks to VoTU for first discovering the 'aquarium' phenomenon. Putting it all together makes this exploration possible...enjoy!
(PS - This trick works on all the lakes and rivers in ZG. There's another 'hole' up north, so you can hit every spot. That, and a slowfall, can get you to just about any point inside the instance while skipping mobs.)