I've mixed moss and orchid mix, and my 1.1 FWCs love it - they never use their hide as they prefer just to cruise beneath the substrate, and only come up for water and food (and watch TV - they seem to be really interested anytime I'm watchin cartoons).
:I am about to change out my substrate in my fwc's cage and was wondering what is the best substrate for them. I know he likes to burrow but won't burrow in this substrate. I have those bricks of cocnut bark in there. He doesnt like it. What is the best i could get for him.