It is probably best to begin with a product that is basic and simple. The dust or scent of perfumed or deodorizing filler materials may be disturbing to some cats. Others may prefer fine sand-like filler or even shredded newspaper. If you decide on a new brand, your cat might adjust more smoothly if the two litters are mixed for a time. The most important thing to encourage litter box use is cleanliness.
Cats are very clean animals that avoid foul-smelling and damp places.
Consider not what you think is clean, but what your cat considers acceptable. Change the litter completely and frequently at regular intervals, using the manufacturer's recommendation as a guideline. Each cat has its own tolerance of litter box contamination and may avoid using the box if it is too dirty. As a rule of thumb, provide one litter pan for every cat in your household. If you have more than one litter box, you may find that some are used more than others.