SAKRET is a sign of pigment powder; you could add the cement for giving a specific color. Be careful before to use it, since it can stain SAKRET dust in some areas. Work as soon as you can, so that the dust SAKRET does not get time to sink in the rock. It is difficult to remove.
First, brush the dust as possible and throw them away. It is not possible when the material is wet. Add 2 tablespoons soup. Add liquid dish soap, in 1 gallon of warm water. Dip a brush to scrub with soap and water and rub on the surface on the stone until it is clean. Spray over the stone by a concrete cleaner containing muriatic acid, the color of cement is still visible. Wipe the stone with a brush till they are totally clean. Rinse the stone and then let them dry.