Smugglers with Bags of Holding

[Sir Hawkeye]

One solution might be to make all people entering a city pass through a dual-sided portable hole; All smugglers would be sucked into the astral plane. This has the added benefit of making the city more defensible, as it would not need gates.

 

[KarinsDad]

Actually, Bags of Holding are a piece of cake.

They are 2 feet x 4 feet, so they are easy to spot.

You can puncture them with a dagger from the outside and poof. All gone, just like busting a balloon.

The authorities would have no problem with them.

 

[Darkness]

Drug dogs couldn't smell them, no need for bulky airplanes, and you could bring a LOT at one time.

How about using astral or ethereal (as appropriate; not sure which) dogs, then?