I use reptile moss and moisten it whenever i cat it as dry, just keep it moist enough that it absorbs allt he water and there isnt any, if very little, left int he box.
Coco Fiber and/or Sphagnum (long fiber) moss. I don't know what "reptile moss" is made of, but it sounds expensive. heh It's too moist if there's standing water in the hide.
I use good old peat moss. The boxes are sprayed and the peat is turned about four times a week. I turn the peat to prevent clumping and to check for eggs .
The thing about vermiculite and why i stopped using it was that the geckos would get themselves nice and moist then come out of the box wearing a vermiculite coat.