Feminine Hygiene - Ladies, please help me out!

Okay so I've read in numerous magazines, books, whatever.. that the vagina is self cleaning & you don't need to wash it with soaps or use douches or the cleansing cloths. But when I get in the shower, I wash everywhere including that area. Is there anyone on here who doesn't or can tell me what exactly "self cleaning" means & why they tell you to not use soaps, douches, or the cleansing cloths? I'm so confused! Thanks!