Nature as example
Most people know the word „osmosis“ from school- biology class. It is the movement of liquids through a semipermeable membrane. The movement of liquids by the electro-osmosis-method works exactly like this.
Water, which should leave or which should not go into the capillary system in the brickwork, will be moved towards the desired direction by an applied electrical voltage. Thereby we use the fact that water in a current flow always moves from a plus pole to a minus pole- simple but effective.