Can you change the gender of the Pokemon in the hidden grotto?

Question

Before I interact with the Pokemon in the grotto, I always save. If it's not the right kind of Pokemon (in terms of gender or nature, I reset and try again. When I do, the only thing the seems to change is the nature or level. even for a Pokemon like clefairy (male 25% female 75%) the gender doesn't change.
Am I wasting my time?

Answer 1

Yeah, you kinda are wasting your time. The Hidden Grotto respawns(Well, 5% chance it will) every 256 steps. At that exact moment, the Poke'mon's gender is determined. So you can't soft reset the gender.

Answer 2

There is a 30% chance that a Pokemon in the Hidden Grotto will be female. However, Pachirisu, Combee, Corasola, Minccino and Nidoran(both genders) have different percentages. And Metang and Ditto cannot be female at all. However, once the Pokemon have been generated, it's gender is set, so it cannot change by soft resetting the game.
Source: http://www.serebii.net/black2white2/hiddengrotto.shtml