I would be very surprised if there is not some random checking of incoming luggage before it gets out on the carrousel for pick up - probably electronic or perhaps canine sniffers (which I have seen in use at Dubai searching for explosives).

Heaven help the OP if he gets caught. A UK national was arrested, jailed and deported for having the illegal substance in her system - they tested her on arrival (and no, you don't get the chance to refuse - if the authorities want a blood sample/urine test - they get it).

Signature line > "You can't fix stupid"