I fly with my Reo like every couple weeks...
Here's what I do - may not be right for everyone, but it's what I do.
1 - juice and batteries are packed up, sealed carefully, in carryon. Never had a problem.
2 - Literally outside the airport, or sometimes in the bathroom, I take the bottle of juice out, and replace it with an empty bottle.
3 - I use the "Fancy Italian Bottel" - and I have a cap, with a peice of silicone covering the hole (trimmed the end off one of those silicone things that came on a carto - and stuffed it into a bottle cap). If you use classic Reo bottles - just pop a solid top on the full juice bottle and an empty in the Reo.
4 - I remove the battery, and have a little battery case it goes in.
5 - If easy enough, I close the airflow on the atty. And then wrap a small peice of tissue around it, maybe tucked in the top too - to soak up any seep of juice.
That's it. At the far end, I re-swap bottles, pop the batter in, open the airflow, and vape while I wait for luggage.
That what I do.
My Grand must have something like 50 flights behind her...
I have to fly out of town for work on Sunday. Any Reonauts have any flying tips? I'm thinking I'll have take my Reo in my carry-on disassembled.