ewww ewww ewww! The idea of actually getting bath water - water I've been sitting in so it most likely has soap, dead skin and bacteria in it - in my vagina sounds pretty gross to me. Why would you want to introduce those elements into your vagina? Would you put it in your mouth?
Of course, if you're talking a freshly drawn bath that you haven't been in for more than a few seconds, then maybe. But still, the vagina is supposed to be self-cleaning. If there is something wrong with the natural pH balance, bathwater most likely isn't going to help.
As for if you've given yourself some kind of 'water embolism', probably not. It would have to get past your cervix and I'm pretty sure just sucking in your abdomen doesn't create enough force to do that.
I would suggest that if you really want to cleanse your vagina with water, you get a proper douche and use sterile water.