I got the dna kits but never did do it, It as free to get the kit sent to you but its like 17 bucks for the actual test to be done, and you'd have to either A) pull a fresh feather with blood on it from the chest(they say the chest is best) and actually they suggest at least 3 or B) make thier toe nail bleed by cutting it to short, and putting the blood on a plastic disk they send ( just like doctors do for cultures) I would suggest the feather pulling would be more safe, just in case you can't get the toe nail to stop bleeding
and yes i'm the one who know's of a few different quakers that were DNA tested to be one gender and turned out to be a different one
I've got a way which i posted a couple weeks ago, i'd say for me its 95% correct and it's free! but thats just with me, I took in account all my birds, which ones I know excatly are boys and girls, and then used it on them, then the one's i'm unsure of
all you do is get a string, or a piece of thread and a small light wieght nut, tie it to the end, put it over the birds head, Make it stop moving(the nut and the bird not moving helps LOL) and if it goes in circles it's a female if it swings back and forth it's a male
this technique has been used on pregnant women for years, I just heard about it bieng used on birds, my b/f's dad has been doing it for many many many years on his pigeons, and he said its between 85-95% correct, it depends on how many you have though