Presumably all obsessions are extreme metaphors waiting to be born. That whole private mythology, in which I believe totally, is a collaboration between one's conscious mind and those obsessions that, one by one, present themselves as stepping-stones.
I would say that I quite consciously rely on my obsessions in all my work, that I deliberately set up an obsessional frame of mind. In a paradoxical way, this leaves one free of the subject of the obsession.