Prefolds or flats would work great. Or, you could sew fleece on one side of the microfiber inserts and lay them in the shell. I did that for use with Flip covers. I just used one of the many fleece baby blankets I had.
I'm Karen (43), soon-to-be divorced single mama to Noah (11.23.04) and Elijah(2.11.09). Trying to get right with myself and get my life back together. Looking for my zen place in the universe.