Reply to all,
I use paper towel only. Going on 2 years. I started, day one, with a well planned traditional layerd bottom, and quickly became concerned of loosing track of feeding. Plus, I could not stand the muck.
I house tree frogs, change it every other day ( sometimes 3 days) . If you make that layer thick enough humidity is never not a problem. I change it during the day- they never know I was there !

FYI- I have an experiment going. I raise my own crickets. I have purchased -very thick- 100 % cotton quilting fabric. ( quilt batting- it is the thick fabric that quilters use between the 2 layers of a handmade quilt) I have little pieces of the fabric in with the crickets right now. If the crickets do not eat it I am going to start using it as substrate. The actual size of the batting is like a single bed sheet. If this works, I will be cutting/customizing the sizes for my bottom of my enclosure. My plan is to re-use it. I will have many, many pieces and be able to wash it ( hot water in the washing machine ) and dry it in a nice hot dryer !!! Well' see?

Lynn