I don't have extensive experience in cleaning bricks but this is how we are doing it. That was very much the 'royal we'! It's a bit of a laborious process which starts with digging through the piles of brick and rubble to pick out the whole bricks. These are then transported by wheelbarrow to a pile next to the 'cleaning station' which is a stack of old breeze blocks covered in plastic. The bricks then have the mortar chipped and scraped off using a builders hammer or if it is really stuck on, by hammering a cold chisel and hoping that the brick doesn't break. Then the dust and remaining mortar is brushed off, the brick is graded - we have a range of brick sizes (65mm, 70mm, 75mm depth and a variety of lengths) and then the brick is stacked on the appropriate pallet. It's all very labour intensive, but the resulting rebuilt walls are all so reassuringly sturdy compared to the original buildings and of course re-using the original bricks is cheap and eco friendly. In fact we checked on the internet and reclaimed bricks cost £1 to £1.20 each so bearing in mind that approximately 6000 bricks have been cleaned so far it is a significant cost saving as long as we don't place a value on our time - our labour is free!