i use perlite, which carries every bit of the danger vermiculite does. key is to know when your eggs are due and to keep constant watch over them during that period. the vast majority of mine hatch out between lights out (~8 pm) and 1 am. seldomly they hatch out mid-day. by removing them quickly, you can tweeze/spray off excess incubation medium. if you are unable to tend to eggs like this, you could try something like peat moss, which i have successfully incubated eggs on, sponge/foam, or anything anyone else recommends.
you'll definitely wanna keep things nice and cool though.