It is amazing how often articles about plants fail to mention their sexual "states", it can be hard to get a straight story sometimes. It seems whenever you discuss a plant that is clearly documented as dioecious, someone will chime in about knowing of a single plant somewhere that is bearing fruit. I don't have the luck to get one of these "fluke" plants, I always plan on planting a few if documented as dioecious.
I've never tried calabash nutmeg (to my knowledge), I know it is used in some African and Caribbean cuisines. I tried to start it from seeds several years back with no luck, however the seeds may also not have been very fresh. I do have a couple of seedlings in the orchard that I got locally. They have been growing slowly but steadily; they might be reaching the point where they will start to speed up.
I know we are getting further off the topic here (nutmeg) but there is another annonaceous plant where the seed is eaten as a spice (although I think the spice is the pod as much as the seed) -- Xylopia aethiopica. It is also an African spice. I don't know if that one would be of interest to you.
John