Peter, thanks for mentioning muriatic acid...I'm glad to hear that it does work. I have looked at it in the hardware store before, and it does sound like strong stuff. I had been resisting using it but I have tried Simple Green and then TSP and they did not work too well. Immediately after the wall was dry the dusty look returned to the bricks. Guess I will have to use the muriatic acid and just be very careful not to get it on the floors. And I will wear the safety equipment. Thanks again.