I keep ball pythons, boas and carpets. I use Cypress and Coco husk chips. Cypress mulch holds humidity well but like someone else said it is a coarser mulch and can be in hard chips. I have used it alone but is “flattens” down in the bottom of the tub more than I like. What I do currently is mix cypress and coco just to make coco last a little longer. I have liked mixing it about half and half and it has worked well for me.
I use sani-chips for juvenile ball pythons because that rack holds more humidity and doesn’t need the coco. But all adults are on coco/cypress or a mix of both.