The ones that I've made for my tank and my son's tank look very much like Robzilla's.
I took one by my local LFS to get his input on it. He asked that I make some for him to sell in his shop.
So we've sold about a dozen of them thus far and we need to make some more.
This is what we've been calling the Grand Cope-a-Cabana. BTW, it's 8 inches long and the one in the photo still needs to have more holes drilled in it.:
This is the 4 inch version that I have in my tank:
Normally I flush them with saltwater, shake out the excess water then seed them with LFS bought pods. Place it in the back, behind the rock (out of sight) and let the little guys and gals do what comes naturally. We started our most recent tank during the first week of February. Added a Green Mandarin in mid May. The Wrasse and the Mandarin are still doing great even after such a short period of time.