Brushing:
Using a strong brush, you can remove efflorescence with ease. Efflorescence is water soluble, so it may disappear through natural weathering, but if you are looking for a faster solution, brush off the stone.
Pressure Washing:
Using pressurized water will help dissolve efflorescence quickly but make sure to dry off affected surfaces properly afterward to prevent the crystals that may remain from reforming the substance.
Diluted Vinegar:
This natural substance is an easy fix for removing efflorescence. It is much less harmful than industrial chemicals and most homes normally have this on hand.
After Care:
After you have removed the efflorescence, you should consider putting a water-repellent or silicone coating. It is VERY important you apply these correctly because if you do not they can cause more harm than good.