When I had the issue I was using Cypress mulch bedding, it wasn't soaked but moist, and the driftwood started to mold where it was touching the bedding. I immediately took it out, sanitized it, threw it in the oven and baked it, changed the bedding for new and tried again...again it molded....so I made the PVC jungle gyms, they don't mold LOL
The snake was fine, no issues...I was really concerned about RI, but nothing thank goodness.
I'm going to try the cork bark now...