Abstract: A method details injecting water into a gas turbine engine to facilitate cleaning an inner surface of a combustor. The method comprises removing an axial fuel injector from the combustor, wherein the fuel injector includes a nozzle stem, and inserting a spray nozzle assembly into a fuel injector opening created within the combustor when the fuel injector was removed, wherein the spray nozzle assembly includes a popet nozzle that is coupled to a nozzle stem that is shaped substantially identically to the fuel injector nozzle stem removed from the combustor. The method also comprises coupling the spray nozzle assembly to the combustor such that the popet nozzle is inserted substantially concentrically into the combustor, and injecting water into the combustor through the spray nozzle assembly.