I am burning the Enviro Bricks in a Tulikivi masonry heater (fireplace). These bricks are great. Clean, no woodpile mess, very dry, ash is reduced by about 75 percent. Relatively easy to start with firestarters, and easy to reload. I’m burning 40 pounds per night. Great heat output. And so easy to store in the garage, just stack them up against the wall.
The “local” (VA) Tulikivi dealer let me know about a similar brick product, but the Enviro Brick were much more affordable.