Rae - greys are different, they are typical tree frogs, they need substrate and humidity, you may want to check care sheets.

for waxys i actually was thinking to do something more natural looking then just felt looking cover that I have for the bottom, but couldn't come up with anything. coconut fiber will be powder in low humidity thus respiratory problems and death because of that may occur. anything else - impaction risk unless tong fed. but I just love to see them hunt, besides they poop and pee a lot, so it is just easier to use whatever works.

kitten have you seen bbc videos on youtube:
The Waxy Monkey Frog - YouTube

and this one - typical feeding time :lol: although the set up is not the best one, and looks like humidity is too high
Waxy Monkey Frogs are spoon fed - YouTube