I have finished reading that post and can offer my opinion. I apologize in advance for those who it will sound harsh too.
To be honest I see no real reason to "discard" you seeds as it is said in that chart. Of course you are free to do anything you want with your seeds, but this is a little in the mythic area. Sounds to me like the method women used to "predict" babies sex, by shape of belly, before ultrasounds LOL. ( it's not the most SF I heard of )
But on the positive side, there are always feminized seeds, from trusted breeders you can be almost 100% sure they will be girls. I say almost because nothing is guaranteed when it comes to genetics.