I read through the link with much interest Sean. Lots of good discussion there. It seems the guy was a bit of a salesman, and couldn’t actually deliver a functional product. There’s mention in some sources about boron, and perhaps up to 20 different dry ingredients, but PVA glue seems to be the binder. Such a product could work for temporary protection but not much more.
I still see differences in the way the original composition behaved under a torch compared to the recreations, but the takeaway I get is it isn’t a long term refractory material one can rely on.