Comment by kakacik

Price of water from water fountain (to be found on basically any western airport and most non-western I've ever been to) - 0.

I get your approach, but say where we live (Switzerland) if you have something not tightly around your body like a fleece jacket, you have to take it off and put it through scanner, this is default. Sometimes they still ask me to go down to t-shirt even if its obvious I don't have anything in pockets.

Not worth the hassle for something that is mostly free and probably healthier compared to plastic bottles stored god knows where and how long. I'd imagine if they catch you, you are going for more detailed inspection since its obvious you didn't forget 1kg bottle in clothing you wear by accident.