Ceramic Glazed Bricks for heater core and riser

Hello,

This is my first post. I tried using the search function to see if my question has already been discussed to no avail.

I am in the process of making my first rocket mass heater for my greenhouse.

Here is my question:

I came across from free bricks that were used in a bread oven. They have a ceramic glaze on on side. Does anyone have any thoughts on using them inside the heater core and heat riser?