Led using the right variation and managed to get my rope stuck on a block in the right-hand crack, despite extended efforts the rope had to be cut. it appears we were not the first party to have done this. note for the future: rappel the left variation.
"After the first glass, you see things as you wish they were. After the second, you see things as they are not. Finally, you see things as they really are, which is the most horrible thing in the world."
--Oscar Wilde on Absinthe