Anyone remember the Ackers Trust wall in Birmingham? It had a classic, 10ft wall to a roof exiting onto a huge ledge made of 1ft thick concrete with no holds beyond the lip, all above a shallow pebbly landing (it was outdoors).
After much puffing and flailing, and ultimately failing, with both hands and a heel on top it transpired that the way to do it was to hang free facing out and invert so that both feet went first and once your hips were over you were sorted. This did mean that you were hanging upside down 10ft above a shallow pebbly landing looking at breaking your neck if you fell but somehow it didn't seem as scary then as it does sitting here now.
I am yet to employee this technique on the rock and it appears this was time wasted showboating when I could have been practicing something more useful like one armers