I wish I had seen this thread when it started. I do quite a bit of seed feminzing and have tried many various methods including the ones stated above. This is completely from my personal experience in the environments I have created and I am certain results will vary, but I have had very little luck with the above methods as a high percentage of the seeds have hermaphroditic tendencies. The method I have personally had outstanding success with is foliar stress using a 25 to 35 ppm concentration of colodial silver.
This is how I do mine:
3 days before changing light cycle to 12/12 spray female plant generously with colodial silver solution, and continue every three days from there on. The plant will begin to produce male pollen sacks as well as female flowers, as the sacks begin to open, I take the plant and shake the pollen onto a budding female with the same light schedule. Toss the first plant and harvest the second when the seeds are ripe.

For me, I average 90 to 95% of the viable seeds harvested to produce female plants.
Best of luck.

JSG.