Hi there!
I think for your situation (21 and counting) aspen is a good bet. You will easily get your humidity up with some well placed balls of damp moss that you can spray and respray. It solved my aspen issues.
I fed Sniper tonight and he did everything wrong. Dragged the quail through his water, ate it sideways and got dirty LOL!
It looks great, and I'll give it a chance because even though he got it on his wet prey there is nothing sharp to worry about. It is great with humidity and there is not dust.
It has some soil like properties.
I think aspen might be a multiple snake owners best bet.