Clean new masonry surfaces by waiting from 24 to 36 hours for the mortar to dry and then using hand tools to remove any large pieces of mortar. Wet the surface with water, and scrub the surface with a brush and an appropriate cleaning solution. Dilute muratic acid with water using one part acid to nine parts water for use on red brick. For historic masonry work, proceed with caution, and test the cleaning solution before beginning the overall project.
The acid solution helps to remove any small splatters but cannot remove large pieces of mortar that stick to the surface. A boat paddle helps to remove these materials from large areas quickly. Use a hammer and chisel to remove tightly adhered mortar.
Before beginning the cleaning process, check with the brick manufacturer regarding the appropriate cleaning solution for brush and bucket cleaning. Some of the commercially available solutions contain the same hydrochloric acid in muratic acid but also include buffers that prevent the solution from damaging the brick surface.
Use a garden hose and sprayer to wet the brick before beginning the scrubbing process. Work around the building just ahead of the sun when cleaning so the brick does not dry out as you scrub, but dries quickly after you clean so you are able to check for remaining stains.