I saw a guy buying a bag of perlite that big last time I was at the garden center. I'd have to strap it to the roof of my car, it surely wouldn't fit inside my lil Focus. I couldn't help laughing out loud when I saw it! It looked like a hallucination of a gigantic bag of perlite walking through the garden center!
I'd never seen a bag of perlite that big before.
The problem with Kitty litter is that it's not fired at a high enough temperature so it becomes that mud you speak of. That's why I chose the Napa everyone said it doesn't degrade like kitty litter or granulated limestone. I used that in some pots for lime-lovers and it disolved creating a nearly solid calcium brick!
I don't have any water testing kits since I don't keep fish anymore but I will put a handful of Napa in a jar of water and see what happens to it... stay tuned!
Here is a bit of Napa underwater, the shot isn't really this blurry or water this salty but rather all the napa is gassing out and filling with water, there's billions of tiny bubbles rushing to the surface in this tiny jar. The larger pieces floated to the top as I filled the jar cos they hold more air. There was a lot of dust so I rinsed the Napa three times to get clear water.
My empty pot tests are almost totally dry. Lower 1/3 of both pots are still slightly moist at the end of 2 days, so it seems like "good stuff" so far.