Drinking is by no means necessary for swaying pink, but it is showing good results in our stats. And if you got multiple boys drinking rarely, I think it's a good option to consider. I suspect alcohol sways both via its effects on the body and on the mind. Certainly many boy moms can benefit from some relaxation!
There's no one single way to sway and there are undoubtedly many factors we are unaware of that sway in addition to the few we know/suspect and try to control. Every child's gender is the unique result of myriad variables. That's why atomic is so big on driving home the fact that there is no single magic bullet that will gaurantee your DG.