Although we kept adding more and more layers onto the walls. Once I felt it was enough I decided that I wanted more of the mold effect. I tried a few different ways of creating the mold/slime on the walls. PVA glue being splattered, PVA with flour and more, but the most effective was elephant roll. I torn lots of little strips of the roll painted them and then dipped them in PVA glue. By constantly piling strips on top of each other it created a great dripping slimy mold effect. I decided not to do it all over the walls in every hole because I thought it would loose its effectiveness.