Mold on moss with dry start

[Lauralana9]

I'm trying to use the DSM with a piece of driftwood. I ground the moss up and mixed with greek yogurt and put it in a plastic shoebox and covered with saran wrap. It is now growing mold. Everything I can find online is about plants amd mold with dry start. The answer is always peroxide but I can't use that on moss. What can I do? So I have to scrub it down and start over? Should I have used regular instead of Greek?