How you remove the soot from fireplace brick, stone and surrounding walls is very important. If you do it the wrong way the soot will be set in and you will have to stain kill and paint to remove it from walls and it will probably never fully come out of bricks and stone.
To remove soot you want to use a SOOT AND DIRT REMOVAL SPONGE. These are sold in hardware stores, home centers, amazon.com etc. They look like a big brick eraser.
To use a Soot and Dirt Removal Sponge DO NOT wet it. You will use it dry to “erase” the soot. Rub firmly with the eraser over the soiled areas. Continue to erase until all soot is gone. Don’t rush this process. If you don’t remove all the soot this way, when you touch it with water it will set in.
Once all the soot you can see is removed you can wash the area with hot water and TSP (Tri Sodium Phosphate. Buy this at home centers and hardware stores.
If you have tried to wash soot off of walls and you have black smears and haze you will need to stain kill the area and then paint. You must seal the area (KILZ is a good product) before you paint or it will bleed through again.
For brick that has set in soot, wash with a strong solution of TSP and hot water. Use eye and hand protection and scrub with a stiff brush. It will probably still leave discoloration.
TO CLEAN FIREPLACE GLASS: Go over the glass and frame with the Soot and Dirt Removal Sponge. Once you have removed all the soot that will come off, wash with undiluted alcohol. DO NOT do this around open flame or pilot light on gas fireplaces.