Reef Central Zoa Thermos Trade!

[Dactyl]

this will be my first time doing this so i want to do it right.
does anyone have any other tips for the best way to do this?
ive heard you put the zoos in zip lock bags in the thermos. and i may add something to keep it cool enroute.
also im guessing when you receive the other persons thermos and remove the contents you simply mail them back the empty thermos right? just being cautious.