Interested to hear how your aircrete refractory experiment went. I have been working on something along those lines myself. Built myself a very nice foam generator, but then couldn't decide what commercial refractory mix would be the best candidate to begin experiments with. After all, the stuff is pretty pricey. A lot of it is very dense and full of grok, which I don't suspect is going to stay suspended in the foam. After all this, I stumbled upon a recipe for a foamed clay ceramic refractory mix that I am playing with at present. If you're interested, it can be found by searching for recipe # 34 in Patent 3,944,425.
So, google search patent 3,944,425 and you'll find it.
You can follow my adventures working with it here.
https://permies.com/t/152407/ceramic-glass-batch-box-roof