I apologize for my lack of clarity on this system's use. I, too, would love to see a video of it being used, especially with a scantily clad hottie! Unfortunately, making videos is beyond my ability. Maybe we could pressure Nick into filming something?
Be that as it may, I will try to explain things a little better. The knee ascender takes the place of the more common hand ascender with a foot loop, as used in a typical rope walker setup. It has a one inch nylon web sewn on the bottom of the Croll/knee ascender, with an adjustable size foot loop on the other end. The length of the strap should be set so the Croll comes to about the top of your knee. Some length fine-tuning here can make a big difference. The Croll is advanced up the rope by the bungee cord run through a Revolver carabiner clipped to my harness belt then back down to the Pantin strap. The bungee has small clips on both ends.
So, to use, I first attach my Hitch Hiker to my rope as I normally would and clip the advancing strap to my Torse shoulder harness. Clip on the Croll and Pantin. Now as pictured with the HH set on the bridge ring, in a normal work position, you will need to hold onto the rope to maintain an upright position for walking up the rope. You can run the HH higher up on your chest by using a short tether for a more hands free climb but I don't find that as comfortable.
The thing I like about this setup is all the advancing is done below the HH. This works far better than using a hand ascender above because you can keep your hitch adjusted nice and tight and everything still advances smooth and easy. With a hand ascender I would often need to do a double stroke with the Pantin foot to take up slack or run the hitch real loose so it would self-feed, which I don't like to do.
The reason I run the Revolver off my waist belt as opposed to the bridge ring is it orients the roller in the proper direction and it keeps a more constant tension on the bungee even when not traveling up the rope.
David