Black rot in terrarium, how to get off of background

[Fishkeeper]

I have what looks and acts a lot like black rot in my micro orchid terrarium. To get rid of it, I have a pair of sharp scissors, a lighter to sterilize the scissors, and a large jar of ground cinnamon.

I plan to take each orchid out, remove all the moss from them, and cut off the rotting parts, sterilizing and cooling the scissors between cuts. I'll cover the cuts in cinnamon, then set them up in a temporary terrarium, not touching each other, on fresh sphagnum. Hopefully that'll get the rot out of the orchids.

My question is, what do I do about the background? I'll be replacing the sphagnum, but I have cork bark and Hygrolon (plastic mesh that acts like sphagnum) in there as well. Is there any way I can get the fungus off the background, preferably without taking anything out of the terrarium? Will it die off with no hosts if I take the orchids out? Can I get it off with cinnamon?