My mother buys a very specific litter for our cats. She likes the clumpy kind so we can use the litter for longer. Unfortunately, the shops around our place all carry the rocky sort (well I don't know if that's the right word, but you can't really sift through it because all the particles are too big to go through the special shovel that we've got). So my mother dragged me off to a grocery store over by where we used to live (and she didn't know how to get there by car - because I refused to walk - so what should've been a 10 minute MAX trip took around 30) and, wow, they were all out!
We came back home and I was left alone with my marzipan swirl pastry (and the cats, of course) and First Blood (not sure if I enjoyed it or not). Mom comes back toting a 4 liter bag of crystal litter. Really, I can't describe it as anything else. There's opaque white crystals with the occasional opaque dark blue crystal. That said, it's meant to be super absorbent while being really light; I could lift the bag with a finger whereas I'd need my arm to lift the same amount of sand litter.
So she pours it into the litter box. The cats are intrigued (I think they thought it was initially food, because the bag is the same sort - meaning it makes the same noise - as the one that their food comes out of), and she deposits one of them in there. The other cat looks on and sticks its head in for a better look.
The first cat, Multi (because she's multicolored, geddit?), digs around until she reaches the leftover sand that's still in the box, and promptly does her business in that. Meanwhile, the other one, Swiffer (because he's white, and he used to hide under the furniture and come out all dusty), has moved away from the box and sounds like he's crunching on something. It takes us a moment to realize that he's eating the crystals.
We try to get him to spit it out, but he runs away with it still in his mouth and eventually swallows it. But hey, maybe it'll work like one of those stomach sponges from the 50's.