I know moss is used sometimes during shed time & also some keep a ball of moss in the enclose like a wet sponge to keep humidity up but I dont use any of that stuff so i cant answer. But there is no way its 50-60% in there if its wet. Your thermistat for humidity is not reading correctly. My enclosures are around 58 with large waterbowls and their dry ss a bone to the touch. I'll ask a couple other guys i know on here to see what they know.
Several of us just use butcher paper or neespaper because its easy to clean & disinfect.