You can stress a female to turn hermi but not enough for a complete sex change.
Conditions will not totally overcome genetic coding and a bean is genetically coded to grow to be something or another and that is what it will do unless conditions cause slight changes, like in the case of a hermi.
 
If you use regular seeds it is a roll of the dice, a crapshoot. Sometimes it come up 7’s and sometimes you get snake eyes.
 
About five years ago one of my friends asked me what he needed to start growing and I helped him put together a better than average setup, as good of one as he could for what he had to spend, and he purchased a pack of 10 regular beans and one did not pop, one that popped did not push up through the soil and the rest were all males.
 
You just never know when using regular beans. With feminized beans you have less chance of getting a straight/true male than you have of being hit by lighting and living and the most you have to worry about is keeping them alive and if some or all turn hermi. But if you do things right whatever number of plants you end up with you will have gals.