I was cleaning up the patio this weekend and noticed a big, fat seed pod on one of my bearded iris. It's the pink one with orange falls. Although I had several in bloom at the time so it's possible it's a cross.. So I'd like to try to grow the seeds. Has anyone done this before?

How long till the pod matures? Should I wrap it in a coffee filter in case it opens when I'm not looking? Any tips on sprouting the seeds or anything else? How big are iris seeds?