I tried this method twice and it worked both times.
I turned cold water on at my sink. Then I stuck my hand into the water and raised my wet hand over my head.
I then let 2 drops of water hit the top of my head, dried off my hand, and walked around the house for an hour until the water droplets dried off.
Once that was finished I spit on my germinated seed and WALLAH!! female plant both times! I swear!!
This other method sometimes works too..................pray to the pot god