In an inkjet printhead using a gas flow, typically air, to deflect select drop into catch, gas flow (air) ducts are employed to direct the air across the drop trajectories. Improved air ducts include liquid flow channels in a wall of the air duct are provided to allow ink to be removed from the air duct without disrupting the air flow in the duct. A process for cleaning the air duct using the liquid flow channel is also provided.