Well, this is just a theory I am testing.
I noticed air roots just love to grow along the aluminum foil - that's why I put an aluminum foil wall around the perimeter of the air root grafts.
Two of them started their own air roots.
Also, it's the easiest way to do it.
To keep the humidity high inside, I used coco coir. It is very loose and not packed. I am thinking it'll keep some extra moisture inside.
I will report if it works.
I bought a coco coir hanging basket liner and am picking it apart.
I like to use it as mulch on my tropicals to keep perlite from washing out. It's very permeable when you water, but keeps perlite down.
It also has a bit of something sticky on it. I guess to hold it's shape, so, it stays together well.
The first ever block of coco coir I bought had a lot of hair in it. I would be left with a handful after rubbing it though a hardware cloth screen to break it down. As I hate throwing crap out, I tried to use it as mulch in the pots and liked it.
The consecutive blocks never had quite the same amount...