I use Rutland Brick and Stone cleaner. I have a 32 oz spray bottle that I found in the basement of the house when I bought the place. Don't know if it is still available but it works. Dissolves smoke stains, creosote, and baked on soot. It is an alkaline product instead of acid. I will aso add that I use it primarily to clean the soot off the glass on my buckstove, and when I spray it, the soot runs off and wipes clean with little effort. I know glass is easier to clean than brick, but I dont have the same problem your having.
Just looked on google and found some on Amazon.com
I remember watching my father use the ashes , water and a brush to clean the fireplace brick in my childhood home during spring cleaning and then using a garden sprayer of water to pressure wash the sludge into the ash chute at the back of the fire place.
After that we would use the garden hose to wash out the chute outside and use a street broom to scrub the patio with the sludge.
As a preteen I was amazed that ashes bleached the soot and patio dirt stains away. Now I understand that all my father was having us do was give the fireplace and patio a weak caustic soda cleaning each spring.
"I didn't have time to slay the dragon. Its on my "To Do" list !"
Without being able to actually look at the fireplace I think the smoke box is undersized. That is the area over the front opening and the flue. Smoke accumulates there and the draft pulls the smoke out.
My brother-in-laws fireplace smoked unless he had a fire at the very back of the fireplace. On a windy night it would smoke anyway. I cut and painted with heat resisitant paint a 4" x 6" piece of steel angle the width of the front opening that we bolted onto the steel lintel supporting the brick over the opening. This required drilling and tapping holes in the lintel and drilling holes in the 4" x 6" angel. We used 1/4 X 20 machine bolts. This closed the opening of the front of the fireplace by 6" in height and increased the size of the smoke box. It totally fixed his problem. A double sided fireplace has its own problems I am not familiar with. You are at risk of a fire or at least health problems
I believe you need a professional to inspect the fireplace and make whatever changes need to be made.
Just my 2 cents. Best to ya, NJ Rich
GUNS DON'T KILL PEOPLE ANYMORE THAN PENCILS MIS-SPELL WORDS
GUNS DON'T KILL PEOPLE ANYMORE THAN SPOONS MAKE ROSIE O'D FAT.:eek
WHY DON'T THE MEDIA REPORT LIVES SAVED WITH FIREARMS? WH Pressure?
The smoke on the ceiling will have to be 'sealed' When I worked for a Contents Restoration Company all painted surfaces needed to be wiped down to 'set' the smoke before another coat of paint is applied.
It would be a good idea to contact a Contents Restoration Company for idea on how to handle the brick too. They might have some special products to use.