Here's my solution. It's from IKEA and is only 25¢. Cheap, easy to clean, and if one gets cracked or something no big deal because they're so cheap (though I've used these for over a year and they've held up very well i.e. I still have the original ones I bought). I have twice as many of these as I do cages so that when a bowl is dirty or soiled I can simply just swap them out right away. Also, I've never had one tip.

And for smaller snakes (hatchling bps, colubrids, etc) it doubles as a hide. They also make a larger one in blue that's 75¢. But these are the perfect size to fit in racks and for bps.



You can see how for smaller snakes they double as a hide.