I have used righting poles and ropes here are definate facts
I made my first righting pole too short and it didn't work, I made a longer one and it worked. Its just a lever it has to work the only limitation is how far you get from the pivot point. Further out the more leveredge.
I have used righting ropes on many cats, the under tramp system is neat and great when it works but if you can't get your cat back up throw the rope over the hulls like I did and you will never go back to an under tramp system. The reason over hull system works is you are adding more height to your leveredge by pulling the object from higher thereby increasing the leveredge on the object. When you pull a tree over you don't tie your rope around the middle you tie it around the top