Here's the description from the forthcoming Llanberis Slate guide:
Right of clean sweep of California Wall the crag deteriorates to utter choss; you might think that nothing can possibly climb this rotten area of rock, but you would be wrong. High up on the right is a hidden chimney, which is approached by making a death defying scramble to an ‘active’ belay ledge.
29. Fruit of the Gloom XS **Utter madness. Traverse across seriously loose terrain, removing as much of the cliff as you feel appropriate until you reach the sanctuary of the man eating crack. Climb this to the top and belay with much relief.
[W Perrin, D Rudkin 2000]
I've got a photo of the first ascent (which will be published in the guide) - the main crack looks like a good feature, but the approach appears to be 'challenging'.
On the Dinorwig jamming tip, check this:
http://www.northwalesbouldering.com/newsitem.asp?nsid=450
