There is only one environment appropriate for sperm (can't remember exactly what it is)... anything other than that, will kill sperm.
The only suggestion I would say for gender swaying is temping your fertility. But this can take several months. You learn when your ovulation is approach it and to sway for a girl, the odds suggest to bd 2-3 days before ovulation... female carrying sperm take longer to reach the egg and have more longevity than male sperm that swim faster but die off faster.
Married 12/28/2011- 8 short months later, my husband left me in my 14th week of pregnancy, 1st baby. 
Struggling, soon to be single mom was not what I had in mind for me and my baby. And I'm terrified. Please keep us in your prayers as I search for a job and place to live. Perhaps now is the time to dream big.