It worked for a friend of mine and she got her daughter.
It sort of worked for me. I was fairly sure my two boys had been conceived on the day of ovulation. When we decided to go for number three, we tried the Shettles method just to see if it might influence our chances of getting a girl next time, even though we weren't really bothered what we had. We only had sex up to three days before ovulation for about five months, then when nothing happened we tried two days before, but I didn't conceive despite getting pregnant really quickly both times before.
Eventually we decided the age gap between DC2 & DC3 was more important to us than the sex of the baby, so we reverted to the tried & tested method of sex on the day of ovulation the following month. Guess what? I got pregnant and it sure enough it was another boy. No regrets at all, btw, he's wonderful.
So I guess it might work if you are prepared to be very patient and disciplined.
I'm really interested in trying the shettles method, I have two boys and I really would love to have a girl next as OH doesn't want any mor children after that .... although I can be quite persuasive 😂 I have read up on some of it but I just wondered What you girls did?