I have only seen the word Fanjo on here. I don't know any women that say it.
It is twee, but doesn't sound offensive/awful to me. Something maybe kids would say, like Fanny. That is the first word I heard regarding female genitalia when I was in infant school. My mother was not amused when I repeated the word at home!
I knew a couple of women from Liverpool who used the term, 'me Mary' 
I don't like the C-word! I never use it, no other woman I know uses it because it is used in such an offensive way. I know loads of MNers use it, fine if that is alright for them, I don't want to use it. Same with Gunt, which I had to google a couple of years ago, that sounds gross.
I say Vagina, Vulva reminds me of Biology lessons in school.
Mumu, is another twee phrase I have heard used, and some bloke I used to work with used to talk about 'beef curtains' with other male colleagues, which is revolting. 