To get my glass tank setup to 60% humidity, I covered 2/3 of the screen top with aluminum foil, and then put a towel over that. I also switched to a wider, flatter water bowl (more surface area) and moved it over so it's partially on top of the UTH for increased evaporation.
EcoEarth is pretty popular and widely used, so you could definitely go that route if you wanted to switch up your substrate. Depending on how much space you have in your enclosure, you could also make a humid hide and let the snake be the judge of when she needs more moisture.