I've always used the coarse vermiculite moistened just enough that when you squeeze a handful of it you can only squeeze a drop or two of water out of it. I fill shoebox sized Tupperware type containers about half full with it. I place the eggs in rows in dents that I make with my thumb on top of the vermiculite. The container is then placed where the temperature is about 74F inside the container making sure the place is dark. I also make sure that the container is not close to any electrical field.