I do the same thing Michelle- I mix the water crystals into the soil on ONE end of the tank..keeping it moist and the other side dry...they choos the humidity levels they want. The rotten wood mixed in also helps to hold some humidity!I put water crystals (cricket water) into the dirt on one side of the enclosure. It keeps the soil mix nice and moist. When it starts to dry a bit, add more water and the crystals soak it up and keep it moist for a long time. Its worked great so far.
I got my last 2 pairs from James (like other have suggested you contact). I believe Double D's has a reverse trio availiable (2 males and 1 adult female) for sale. Good luck- I love these things.who sells these roaches?