I just went through this mess as I traveled to Boston to lecture at a conference at Tufts. I had a DEA Rx for water, stating that I should sip it every few minutes as needed, a letter from my docs ( with contact phone numbers if there ws a question) at MD Anderson Cancer Center explaining what xerostomia is and the problems that it can cause if tissues are not kept moist and none of it helped. I had my water taken away at screening. I bought anouther bottle from an inside the airport, inside the after-screening waiting gate store, and even that was taken away from me before I could board. Luckily I was flying my favorite airline JETBLUE, (also and OCF sponsor), and as soon as I sat down the attendant knew to bring me a bottle of water, (arranged on the phone with the agent when I booked the flight) which they replaced as often as I wanted during the flight. On the way out of the plane hatch as they were saying good bye, they handed me another one to get me to the next store where I could buy one. (This is the way airline travel was 20 years ago, when we were not cattle and they cared about us.) But even a controlled substance DEA Rx was not getting me past the screeners no matter how enthusiastic my arguments.... It sucks. My next try is for an Rx for oral balance liquid, and I will squirt it out of the over the counter bottle and into a brown Rx bottle, and have my drugstore type a label for me.