mail it to yourself 2 days before you go, then pick it up when you land, that is the smartest way to do it if it is worth the effort of course, i guess if you have a hidden compartment in something, like if you did a real nice job and hollowed out the sole of your shoe, and made a plug so it isnt obvious then it might work, and even be smell proof if done right, something smell proof that isnt obviously able to hold anything, thermos would not work, its easy to look into, but a hollowed out tube for a rolling suitcase that is smell proof might work.