I'm always interested with this sort of thing crops up. It seems to hearken atavistically to the days of pyromancy and scapulomancy and any other group of mancies you care to name.
In it I see the longing, the deep and abiding longing people have for a sign. As it was in the time of Jesus, and is now. "No sign shall be given you except the sign of Jonas." And that sign, descending into the belly of the beast to return to light once again, should be enough.