This is a fairly common question, or at least was a year or so ago. I believe the consensus is it is essentially impossible. I live in an ancient house that also had brick painted white (apparently this dates back to when brick was the cheapest building material and people wanted to make it look like something else). I tried everything--scraping, a blow torch, muriatic acid, chemicals. I could clear tiny areas, but never completely and certainly not efficiently. I talked to sand blasters and pressure washers. Neither thought they could really do the job. Finally I bit the bullet and hired a mason. I had to pay for the removal of the paint and for tuckpointing the areas damaged by the removal. By then I hated the paint with such intensity I really didn't mind the cost, but it was terribly expensive. The brick underneath was absolutely beautiful--a deep red. If you have other things with a more pressing need for your money, you might want to just repaint the house a brick color (after scraping off as much paint as you can) so that when the paint flakes off it will be the brick. Another suggestion someone made, although I never priced it, was to put a new front on the house--just put new brick over the old. I can't believe that would be less expensive than removing the brick.