Hey guys. I'm fairly new here and actually found these forums several weeks ago when I was googling about the Chandler's litter, and found some of Bretts posts.
Anyway, I tried this stuff several weeks ago since I've used similar cat litter as aquarium substrate for years. I potted up some self-seeded trees from the garden in it - a couple of cedars and a box elder. I mixed it with about 30% sifted pine bark from a general purpose potting mix. They grew but didn't seem enthusiastic about it

I also potted a schefflera in 100% Chandler's. Every time I watered it clay dust would run out the drain holes. In other words it does break down. I don't think it likes wet-dry cycles. Also, even though it seems to hold a fair bit of water, the schefflera which is in the bathroom needed watering sometimes twice a day. It drys out so fast on it's own! With the pine bark mix it stays moist longer though.
But I still don't like it. I've been experimenting with the crushed brick mulch that every man and his dog is landscaping with. You can get a 4-7mm grade, and although it's fairly alkaline at first due to mortar dust, after sifting and washing the pH in the batch I tested fell to around 7.5. I mixed this with pine bark as above. Then I bare rooted the cedar trees and found the Chandler's mix had compacted somewhat. Yuk. But after potting them in the crushed brick mix they are growing vigorously. I also had a Japanese maple which was dying in the Chandler's mix. But after repotting in the brick mix it has new growth after about a week. It is a very open mix and because of this the surface dries out too quickly, though it's impossible to overwater. So yesterday I mixed up a batch using sifted Debco Bonsai Mix instead of the pine bark. It seems to hold a little more moisture now but still drains freely. The only downside is weight. But geez, you can get a trailer load of crushed brick for around $50. And it doesn't look that bad either.