Some experts in cat behavior say cats prefer substrate (what they use for bathroom) to be textured like coarse sand, and definitely unscented (cats' sense of smell is much more sensitive than ours and the fake chemicals used as fragrance in litter is much too strong!); we use So Phresh from Drs. Foster & Smith or Petco and have done so for a long time, with success. As for treats, Drs. Foster & Smith have some really good quality ones that are quite affordable, Feline Harvest by Spot Brand in several cat-pleasing flavors. Just suggesting