Would that this was what I had in mind!
My "bcnu" comes from a much more mundane place. There was television show starring Patrick McGoohan who played a spy who was kidnapped and taken to a secret island where no one could escape. The show was titled "The Prisoner" and can infrequently be viewed in the US on PBS. The occupants of the island would always say, "Be Seeing You" on parting and, if you say the letters b-c-n-u, you come out with the same thing.
Sorry the origins were less interesting than what you found!