I know you said you looked at aspen, but did you look at Sani Chips? It's aspen in a small square chipped form. The chips are very smooth and when I was using them, they were not as dusty as aspen. I quit using them because it was making too much of a mess in my herp room...and the snakes were getting a bunch of the chips in the water bowls. I think it would be good for burrowing snakes like KSB's though.