The So Kleen Grey Basic Clumping Cat Litter is made from mineral granules and absorbs urine into the litter.
The litter simply absorbs the urine to form a solid clump which can be scooped out daily, along with any solid waste. Top up the litter as required rather than emptying the whole tray.
We would recommend emptying the whole tray every few weeks and thoroughly cleaning with a suitable disinfectant.
Clumping litters generally use less product than absorbent litter, so can be more cost effective in the long run as the tray contents do not need replacing as often.