I do my cat litter manually, but the author seems to have overlooked the Litter Robot: http://www.litter-robot.com/ My friend has one and it works very well (for years now). It just uses off the shelf cat litter. The mechanism is 'brute force' rather than optimized, but it works: after the machine senses the cat has stepped out by the change in weight, it slowly rotates the entire cat chamber, causing any deposits to be covered by falling litter even if the cat hasn't buried them by choice, before hitting the mechanical filter that diverts any solids into a disposal drawer. It's purely mechanical, so the odor control/dust level is as good as your choice of litter product. Downsides are that it's a bit bulky and noisy. but there's no DRM and it's so mechanically simple that there's not much that can go wrong with it - it certainly won't bake the cat poop like the machine described - yuck.