Yeah, it worked better than I’d imagined it might. The spray made the ends of the sponge get a bit shriveled in a very “fungussy” way, but left the center the natural yellow color. The effect was pretty striking. The issue now is clustering them in a way that is a good combination of visually interesting and playable. Probably smaller chunks will go on the base with some smaller bits of foliage, while a larger “fungal riparius” will be on a removable base to go in the center, so it can be pulled when units enter the area.