Hmm, I have to admit that after a big BD session I can get a little...err the same. I think it's the fluids that are still leaking out a little. The only real thing that could probably fix it is douching. But I wouldn't recommend it at all, because it's going to wash away the swimmers up there!
There are female sanitary products available, I know there's some deodorants/perfumes for down that that can be used without any danger. Although check about TTC and using them first...Don't want anything to harm the chances.