I´d like to get some other opinions on that statement. Safe or not? Also, this person says they put the cat litter down with kiln-dried pine on top.From my own expierence Cat litter is fine as long as it is UNSENTED AND NON CLUMPING !
Those based on recycled newspaper for instance. Good Mews is one that comes to mind Or wood based, e.g. Feline Pine.
The problem with clay based litters is that they consist mainly of sodium bentonite. This a natural clay that has amazing water retention properties. It swells when it somes in contact with liquid. Besides kitty litters, it is used for plugging leaks in dams and caulking and sealing watertight seams. Imagine what this does to a cat or guinea pig´s intestinal tract if it gets swallowed or the lungs if the dust gets inhaled!