Line the bottom of the brick fireplace with towels or drop cloths, which will capture the cleaning solution as it drips off the brick.
Fill a bucket with 1 gallon of hot water, 1 cup of oxygen bleach and 4 tbsp. of liquid dish soap.
Dip a nylon brush into the bucket and begin scrubbing the top of the brick fireplace. Work your way across the top of the fireplace, then work downward. Dip your brush back into your cleaning solution to rinse as often as you think the brush needs it.
Rinse out the bucket and your nylon brush after cleaning all of the brick.
Fill the bucket with hot water only. Dip a cleaning rag in the water and wipe it over the brick fireplace. Begin at the top of the brick and work down to the bottom of the fireplace. Let the fireplace air dry, and remove the drop cloths.