Cervantes says to soak seeds in cup of water with a birth control pill (estrogen) in it over night and this will increase your chances of the plant being female.
This could be worth a try though, it is a weed afterall, should not hurt the plant.
I have hormone replacement patches....I should sqeeze out the estrogen into a jug of water and pour that into my soil and see waht happens. I'll feed my male with it and see if he turns over a new leaf...lol. He coild be a switch hitter.
I'm gonna try it on my next watering, and not only the boy will get it.....all of them will eat estrogen in a couple of days
I'llget back to ya on it.