OK, simple as this- I included the notion of BCPs feminising plants/seeds/seedlings into this spoof bit because it is fully, COMPLETELY stupid. Human female hormones won't do anything to a cannabis plant, end of story. The concept now has earned the status of legendary dumbness, right up there with the old nail-thru-stem technique for improving potency. The only effect you will get by putting your GF's BCPs anywhere but in your GF is an unintendedly pregnant GF. It's not a widespread practise nor even a good rumour anymore, at least not since about 1972. It's such a mouldy old thought that it's one that now is only stood up now and again for a good bit of ridicule, as I did.
Now, can we please leave this idiocy alone?
And while we're on a similar subject, no dealer in their right mind would give away perfectly good drugs, which they would otherwise sell, by putting them on cannabis. This is a rumour gleefully propagated by LEO and other anti-drug zealots with the intent of scaring some young, stupid kids. It's simply never happened.