We've actually had a previous post about the litter pearls which is really silica gel pearls. There may be some useful information in the following post: http://petoftheday.com/talk/Forum13/HTML/000060.html

It's really amazing to see all the different kinds of litter there are available now. I went to a natural products tradeshow down in Anaheim last year, and I got a free sample of World's Best cat litter from the pet department. It was pretty neat because it was made out of corn and it was flushable and all natural. It worked just like the regular scoop stuff, but had low odor. We also mention in the previous post other options like the recycled newspaper litter. There is also all natural wheat litter too.