Pettex Premium Grey Cat Litter. Pettex Premium Grey Cat Litter benefits from a unique sieving system that boosts the already excellent clumping powers. The Pettex original formula helps create a more economical dust free cat litter, while the natural minerals have sufficient odour control to clamp down on those unpleasant smells. As if that wasn t enough, the unique super clumping properties helps the damp patches in the litter to form distinguishing clumps that can be removed and dispensed with ease.