Funny story...
A few years back a friend was coming home from a holiday in Thailand.
Being a sort that doesn't mind a smoke, she indulged in a little hash why she was over there.
Upon her return she was of course stopped by customs, as just about every other young traveller does on their way back from there.
The officers asked her all sorts of questions, and then proceeded to get the dogs onto her and her belongings.
The dog was quite sure there was something on her, and she of course was quite sure there wasn't.
Well the questions went on for a while, and the bags were searched, but nothing was found, so she was free to go home.
Well, once home she decided she needed a shower after the long flight, and the hassles at the airport.
And what did she find in her pant pocket (the one the dog keep hanging around?) - a small block of hash.
It seems she was so genuinely positive she didn't have anything on her that the officers were convinced.
Maybe the old-timers were right, they could pick a trafficer way before all these high-tech tools were invented, just by their mannerisms (and the beads of sweat!)