★★★★★
Pine Pellets from your local farm store. Usually in the equestrian (horse) section for horse stalls. They sell 40lb bags for cheap. Like around $6! Seems to be the same as the pine pellets you buy in a cat litter section at a pet store, but MUCH more affordable! Works great!
Natural Kitty Litter
★★★★★
Our local Farm Supply Store happened to mention that many of their customers use Non-Medicated (important) chick starter (yes baby chicken feed) as kitty litter. We tried it and it works super well. It even clumps a bit, is a little less dusty and comes in a BIG bag for about $15 CD. We have one cat that likes to eat a bit but it will not hurt them. We transitioned by blending it into clumping clay litter to start and phased out the clay fairly quickly.