I have come across used firebricks for free. Only problem is that the corners are not square. Since I need to cut the firebricks in Half anyways can I use the new cut side facing into the oven so it would look nice and square? I know in the free directions is says to place cut side out. Not sure if this would break down the bricks faster or anything else that might affect the oven. I would still buy new bricks for the oven floor. Thanks for any help you can give as I need to decide if I want the bricks soon!