Thanks for your interest in my work
Its a ceramic glaze that I developed - and I fire somewhere between 1190 celcius up to 1300 degrees celcius- its all a matter of viscosity, size of holes in the containers, kiln size etc.
My coming experiments is trying to find a high viscous, low fired, glaze so I can do this at lower temperatures. And yes, I've also heard from glass people that this technique is well known in the glass world
I also tried with real glass in a ceramic container - looks wicked! - you can see more pics at my facebook page - like if you like www.facebook.com/csckeramik