Hi Bro, I do agree about the process and troublesome and stress to the fish. How I did was
(1) go to the Aquarium shop, bought the fish (2) straight to hotel, put the bag of live fish in luggage to be check-in (3) and immediate to airport ( at Jakarta ). Then it is a challenge, depending on the custom officer ~ if he/she want to let you pass ( so I will buy not more than 2 live fish, as I travel regularly to Indonesia ). Flight is 1.5 hour. I still have the spotfin lionfish and majestic that I brought in from Jakarta.
As for HK, I had brought in live fish only once ( many years ago )and that was before the 100ml liquid in airline was imposed. Cos I wanted to spent my remaining HK$ instead of bringing back the small amount HK$ and the fish is not so expensive. At that time time, I hand-carry the bag of live fish.
Just to share some experience, the thrill of bringing live fish from abroad.