What are the various materials I can use to incubate crested geckos?

I know about Hatch-rite and perlite, but no pet stores carry hatch-rite around here, and for some reason the only perlite I can find in the minneapolis area has miracle grow in it, that's surely not good for incubating.

I've heard about vermiculite, but I've never encountered it before. What is it and where can I get it, and would you suggest it?

I'll probably just order some hatch-rite online, but I was just wondering if there are any other substrates that are good for making an incubation box out of a tupperware container.