Well, its not gunna hurt you, lets put it that way. you'll be fine so long as you do not binge once once get back to reality. and even if you do youll be fine. You dont wanna be throwing up KFC in the middle of your acid trip do you? That would be some haunting shit... If all you have in your system is water at the time of the trip, then all you could possibly be throwing up is water. And stomach acid.