Duty free?

OP, have you ever tried to smash a whiskey bottle? It's not as easy as it looks in the cowboy movies. And there aren't very many hard surfaces in the interior of an airliner to smash it against.

Which is not to say that there is not a lot of nonsense in these rules, governments wanting to be seen to be doing something whether effective or not, and governments seeing a benefit in keeping their population nervous.

You idea makes too much sense for the powers to allow it.After all they didn't think of it

I doubt very much if any liquor is poured down a drain after being confiscated. I suspect it just finds a new home.

I much prefer having duty-free available on arrival rather than on departure. So much easier and it eliminates the hassle of having to carry the purchase(s) around with you. It also eliminates the possibility of your bottle of whatever being confiscated. Wish all airports had arrival duty-free shops; unfortunately they don't.

I buy mine BEFORE leaving Auckland and pickup on ARRIVAL back in Auckland.