sounds very much liek the substrate i use, although that particular one is called "mazy", and is made from freeze dried corn.
Its dust free, odourless and doesnt seem to bother the snake at all. I don`t find humidity to be a problem within the tank but that may be because i use a second water bowl in the hot end to raise humidity.
I`ve been using it for a year now and i`m happy with it.