Hello! New here and a fairly new bp owner. I adopted my ball python 'Haida' back in October. His owner was keeping him on hamster shavings and I discovered he had mild scale rot. I have been treating him for that and hes currently in shed now so hopefully he comes out of it looking better.
Right now he is in a 20g long on paper towel to keep things as dry and sanitary as possible but when he better I have a 40 gallon I want to upgrade him into and will be using cocohusk substrate. I know that wet substrate is typically what causes scale rot so I'm wondering how does one raise ambient humidity without making the substrate wet? How thick should it be? Should I mist or pour in water? Mix it up or just let the water seep downwards?

I will also be using a large water dish and probably some moss here and there but some tips to avoid flaring up scale rot in the future would be great.
Thanks