A descaling slurry is applied to a surface of an elongated metal strip from a nozzle array while the strip is moving in the direction of its length. The nozzle array is positioned in spaced relation to the strip surface and extends transversely to the strip at an acute angle so that the individual slurry streams emanating from the nozzles do not intersect and strike the strip in a line at the same acute angle as the nozzle array. The nozzles of the array are directed toward the strip surface at an acute spray angle in the direction of movement of the strip.