It's a pity this wasn't in force for Brxit. There are about 4 million British expats worldwide, if we had all been able to vote the outcome may well have been very different.
The harm done by weed is nothing compared to the harm done by alcohol, prohibition of that didn't work either. I would suggest that the genie is out of the bottle in both cases and Mr. Chuwit needs to cool down before he collects a bullet.
I was taken to the Floating Market for the first time more than 40 years ago when I was young and foolish, now I am no longer young but even then I could immediately see it was just a tourist trap and so declined the boat trip.
I first came to Thailand 01-01-1978 and have been back many times since but I have never been stopped by Thai customs, not that I've ever been carrying anything illegal.
In my experience this is true but they do also catch the fools that haven't filled in the arrival card or need to find their passport before they to the desk.