That snot is good stuff for plecos, panda garra and sometimes snails will eat it too. Have any of those swimming around?
BTW good chance you will have to rinse and repeat. I had a spider wood do that for weeks even after repeat rinses. Once the tank was able to house shrim, the shrimp cleaned off any new growth until it finaly stopped.
I’m planning on pouring boiling water on the wood in a couple days when I get access to a cooler. And I have a pleco in my 10 gallon, I might move him over if it’s good for him and give him a snack~
I’d soaked the wood for 16 hours in my bath in water that was too hot to touch (not quite boiling tho) to try and prevent this but. Alas. It needs a round 2.