Welcome to our community! I wouldn't replace the substrate with paper towels - it's just going to be a stressor. However, I don't like orchid bark for frogs larger than dart frogs because I would be afraid of the frogs swallowing some instead of a cricket.
I understand your concern about whether or not they are eating, but you have to decide between letting them settle in or moving them in a simple terrarium so you can count crickets.
My last comment is about the humidity. I don't like the huge fluctuations. You want to set things up so the humidity doesn't change much in a 24 hour period.