Abstract: An apparatus for mechanical spray treatment of materials has a container for preparing an abrasive suspension, the container having a stirring mechanism including a stirrer provided with at least one blade, and a sprayer for spraying the abrasive suspension connected to the container and a compressed gas supply device. The stirrer of the stirring mechanism has a comminuting cutter provided thereon in the bottom part of the container. The method for aerohydrodynamic abrasive cleaning of surfaces includes entraining the abrasive suspension flow in compressed gas to produce aerosol particles and directing the stream of aerosol particles from the sprayer nozzle to a surface. Moreover, after aerosol particles have been formed they are accelerated owing to the sprayer design within the sprayer before they are ejected from the nozzle.