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 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 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. <EOS>