that's gross
cleaning up dog pooh isn't difficult. unpleasant, yes, but all dogs do it. humans do it. everything that lives do it (though maybe the rules are altered for trees), I don't blame you though- if I knew someone had poohed in a bath tub, I think I'd avoid it too.
luckily though I take showers. I think their a bit better for you. I was always taught growing up that a bath is just making you dirtier, as the water you are using is..... ugg I don't like to think about it