I don't have an aim but you can ask me stuff here. Or in the morning in the chat room.
One easy way to check the sex is the paper towel roll over one branch.
Basicly you turn one branch to flower while the rest stays in veg. I did that last year outside. The only down side is you lose that branch. But outdoors it wont make a difference because they grow so big.
I think thats the technic you were refering to. I just gave it a shot and it worked.
Let me know if you want a better explanation.