Muriatic acid and a garden hose. A pressure washer can actually make the efflorescence worse by pushing more moisture into the brick. We always use muriatic acid diluted from 4 parts water 1 part acid to 2 parts water 1 part acid. You could also check into Prosoco restoration products. I know they sell an efflorescence remover.

Also, once the efflorescence is removed, the brick should be sealed with a masonry sealer. Otherwise the efflorescence will return.

Without harsh chemicals? PRAYER