I just don't get it. A multi-billion dollar industry driven by the sole purpose of keeping something clean that can be kept clean with a magic block that costs 50 cents.

Its called SOAP people.

Sprays and roll-ons and perfumed pussy plugs and lord knows what else.
Wash the motherfucker with some soap.
Shower!
Take a bath!
If it still smells worse than your feet... see a doctor! Douches and salts and electronic overnight suppository treatments.
Vapor rub and ventilation units; nanites and plastic replacement parts.
What next!?
I am aware that some women have a medical condition, but not that many women. :P

I admit, I stole the idea "Perfumed pussy plugs" from somewhere else. If I could remember I would credit them. I believe it was a woman... hehe

Re knife: Apparently the ones I don't know either. I have met a few. But there are enough to support an entire market of unnecessary hygiene items. I used to babysit for a woman who had 4 shelves of her bathroom towel closet filled with douche. That's a lot of douche.