I dont know if you guys are talking about and explain totally different techniques, but when i was in the Royal Marines we were taught a few different rope climbing and descending techniques without any harnesses and such.
To use the most common technique for rope climbing we were allways told to never rely on on your feet to grip the rope, all your power and grip should come from between your knees.
To help find the correct position for gripping the rope between your knees you should:
1. cross your right leg over your left putting one hand between your knees
2. then pushing your feet downwards you should feel two knobbly bits of bone this is where the rope should be gripped. Its important that your knees are level if you are too grip the rope correctly.
The first shift off the ground is normally the most important one, you get that cracked and you should be away.
We were allways taught speed is of the essence, the quicker you get the better the less tired your arms will be.
It sometimes helps to say to yourself whilst climbing feet, knees, squeeze.
Pushing the rope away from your body with your feet as you grip with your knees will also help, as you'll find yourself almost standing on it.
As i said above, i dont know if this technique is of any use to you guys but i used to use it to climb 30ft ropes with srtandard issue british boots and 22lbs of kit and a rifle on my back (and that was before the b**tards used to stick us in the estuary and make all our kit wet
)
Hope it helps
Ian