I've been wondering about trying to do something like that permanent holder thing our our new Iris tubs. Since we use natural substrate with most of the snakes, it wouldn't present a problem. I'm just trying to figure out if my hot glue gun would bond the PVC coupler to the tub correctly. I may experiment on an old Sterlite tub and see how that goes.

For now we mostly use ceramic ramekins. I like their pure white color so you can see when they are clean, they are kitchen grade, well sealed, heavy and not easily tipped. We generally place them well into a corner of the tub and down a bit into the substrate. Works fairly well but I like that ARS tub design better.