Brick cleaning

[spotit3]

I have a fireplace built from used Belfast bricks. The centre portion has become rather blackened due to the fire smoking at one stage. Anyone any idea how I could clean the brick. Any tips would be much appreciated.

[rugeleyboy]

you can get a brick acid that is pretty good?

[spotit3]

Thanks. Any idea where I could buy this acid or what I actually ask for?

[kazxe]

Any builders merchant would have it or hardware shop
Called brick/patio cleaner, Larsens make a good one quite harsh so be careful with spillages onto tiles/furnitue etc!