I've been using harlan teklad aspen for my bp's and dumeril's, which is nice but dusty... It doesn't smell, doesn't stick, is softer and "clean", and absorbs any liquids well. Humidity in my house is around 60~65% now, so aspen is fine for these guys.
My GTP and scrub have eco earth coco fiber, since it's good for retaining humidity... these species need higher humidity, 70~85% range. But it sticks to EVERYTHING and I honestly hate it LOL.
I just bought coco chips and sphagnum moss from reptilebasics to mix with the coco fiber, or split the enclosures in half with the two substrates. Maybe stick the moss in another section in the corner, just to mix it up a little. Just trying to make things more interesting for my scrub python, mainly.