Ok, maybe i am the only one who doesnt use that, i just go head down and slowly make my way down (no need for kicking down), then spread out prone and start to move back up - kind of like skydiving (when isnt scuba somewhat like that?). The ledges are spaced roughly every 4-5 ft in the main area and can be used to improve your descent for sure, i prefer the non-contact way swooping from one to the next using the lack of flow to give you momentum to overcome the upward flow when you drop over the edge of the ledge. Although i know it is a legitimate method of propulsion i try not to touch the sides - there is already enough erosion (man-made) in the spring - i will warn you that you havent seen so much graffitti in a site outside of downtown, it will be shocking to see the reckless, thoughtless people who have etched their names, etc in the walls.
When i first did this dive i was using my regular fresh water weight and found it a little light, now i add 2# and am completely there hardly even touch my wing inflator until i am down at the bottom and out of the flow a bit, as the flow and my body angle can take care of my descent speed.