Cypress works well. So does coir fiber. I have used both with success. Where the cages are now, I can't have particulate substrates. Now I use the alternative methods below.
Alternative:
Cage liners (or newspaper) plus a shoebox filled with sphagnum moss will pretty much meet the snake's needs.
I use a 2" hole saw and cut a hole out of the side of a plastic shoebox. I cut another hole in the lid roughly center. Fill with damp sphagnum (that new ZooMed $15 moss is the best moss I have used ever in the world) and put the lid on. Then, either set the box partially over a heat pad or up against a heat pad mounted vertically against the cage wall. The hole in the lid allows the moss to dry out in time. Rehydrate as needed.
Another thing that works is a piece of either 1 1/2 or 2" dia PVC pipe. Spray the inside with water. Snakes love PVC pipe hides. My only challenge now is keeping it from rolling when the substrate is paper. A 90 deg elbow on one end helps. My latest one uses a few beads of epoxy putty to support the pipe.
You can get cage liners at the link you provided, or the same product (dimpled Kraft paper) from Uline. I use the dimpled kraft paper plus some newspaper over it - snakes like to hide in the newspaper folds when they aren't in the pipe or moss box.
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Mark