Instead of being afraid of people bringing chemicals in via bottles, just have them drink a bit from every bottle so that it can safely react inside them and make a little explosion in their tummies or something.
There was a post a long while back about how airports should have a machine that's designed to detect and detonate explosives. People who set off the initial detector get put into a special blast room and if they have set explosives (ready to explode, not in two separate chemicals waiting to react) it'll blow them up. Then someone would announce over the PA
"We have just received notification that a first class seat on flight 210AF has opened. Cleanup crew to chamber seven please."
"We have just received notification that a first class seat on flight 210AF has opened. Cleanup crew to chamber seven please."