Originally Posted by
drwilliams
They have no reason to test for drugs, so I doubt the GC measures that.
If you do get swabbed you move to the front of the line. That was taught to me when travelling with a late twenties brown male who had been 'randomly' screened a few times before
The last two times I have been swabbed at YYZ it has been after me and my bags have been through the metal detector / xray, so had absolutely no advantage, as otherwise I was clear to just keep walking.