A turbine engine cleaning system comprising: a foaming nozzle, a foaming chamber configured to receive a detergent and the foaming nozzle; a foam delivery system (35, 36, 72) configured to fluidly couple the foaming chamber with a turbine engine; wherein the foaming nozzle comprises: a wall comprising a thickness between an outer surface of the wall and an inner surface of the wall, wherein the outer surface of the wall is configured to contact a detergent in which the foaming nozzle is configured to be disposed, wherein the inner surface of the wall surrounds an inner plenum of the foaming nozzle, and wherein the inner plenum is configured to receive an aerating gas; a first row of first through holes fluidly coupled to, and extending between, a first row of first through hole inlets at the inner surface of the wall and a first row of first through hole outlets at the outer surface of the wall; a second row of second through holes disposed axially adjacent to the first row of second through holes with respect to a longitudinal axis of the foaming nozzle, wherein the second row of second through holes is fluidly coupled to, and extending between, a second row of second through hole inlets at the inner surface of the wall and a second row of second through hole outlets at the outer surface of the wall, characterized in that the foaming nozzle is additively manufactured such that the cross-sections of the first through holes and the second through holes comprise regular shapes. a foaming nozzle, a foaming chamber configured to receive a detergent and the foaming nozzle; a foam delivery system (35, 36, 72) configured to fluidly couple the foaming chamber with a turbine engine; wherein the foaming nozzle comprises: a wall comprising a thickness between an outer surface of the wall and an inner surface of the wall, wherein the outer surface of the wall is configured to contact a detergent in which the foaming nozzle is configured to be disposed, wherein the inner surface of the wall surrounds an inner plenum of the foaming nozzle, and wherein the inner plenum is configured to receive an aerating gas; a first row of first through holes fluidly coupled to, and extending between, a first row of first through hole inlets at the inner surface of the wall and a first row of first through hole outlets at the outer surface of the wall; a second row of second through holes disposed axially adjacent to the first row of second through holes with respect to a longitudinal axis of the foaming nozzle, wherein the second row of second through holes is fluidly coupled to, and extending between, a second row of second through hole inlets at the inner surface of the wall and a second row of second through hole outlets at the outer surface of the wall, a wall comprising a thickness between an outer surface of the wall and an inner surface of the wall, wherein the outer surface of the wall is configured to contact a detergent in which the foaming nozzle is configured to be disposed, wherein the inner surface of the wall surrounds an inner plenum of the foaming nozzle, and wherein the inner plenum is configured to receive an aerating gas; a first row of first through holes fluidly coupled to, and extending between, a first row of first through hole inlets at the inner surface of the wall and a first row of first through hole outlets at the outer surface of the wall; a second row of second through holes disposed axially adjacent to the first row of second through holes with respect to a longitudinal axis of the foaming nozzle, wherein the second row of second through holes is fluidly coupled to, and extending between, a second row of second through hole inlets at the inner surface of the wall and a second row of second through hole outlets at the outer surface of the wall, characterized in that the foaming nozzle is additively manufactured such that the cross-sections of the first through holes and the second through holes comprise regular shapes.