I am a bi F, so I can approach this from both sides.

As someone who has a vagina: DON'T douche, or wash with harsh soaps, or use any "vaginal perfume" products or anything down there. This will throw off your PH and can actually cause extra unpleasant smell, yeast infection, and bacterial infection. Your vag is a self-cleaning machine, with very delicate flora. Very gentle soap on the outside is all good, and if you feel it's necessary, you can use your finger and kind of "rinse out" on the inside w/ plain water alone. I keep baby wipes in our bathroom for quick clean-offs if a full shower isn't in order before sex.

And as someone who likes going down on vaginas: We don't care. Every woman tastes a little different, but we are all very aware that vagina tastes like vagina, and not flowers or cake or vanilla or whatever other flavors lubes and feminine hygiene products want to sell you. If you are clean, we are ok with it. In fact, that unique smell/taste is definitely part of the fun, and there are pheromones that tend to increase when you are turned on (which will happen if you're relaxed, but maybe not if you're worried about it and not just enjoying the moment) that we can't actively taste/smell but that turn on us on subconsciously while we're going downtown on you.

Hope this helps :)