Disassemble the airbrush and soak all parts except the air valve in lacquer thinner or mineral spirits for one hour. The air valve contains a rubber o-ring that may deteriorate when exposed to corrosive chemicals such as paint thinner. Should paint get on the air valve, gently clean it with soap and water. If enamel paint remains, use a cotton swab soaked in mineral spirits to clean the valve.
Soak cotton swabs, pipe cleaners and a toothbrush in another tray of lacquer or mineral spirits. Use them to brush all enamel paint from the airbrush parts after soaking. Keep cleaning a part until the tool no longer removes any visible paint. The very tip of the nozzle can be cleaned using a twirled piece of paper towel. Twist the towel to a point, dip it in mineral spirits and run it through the tip, much like flossing your teeth.
Apply a coating of airbrush lubricant to the needle, threaded surfaces and trigger mechanism. Lubricant helps the paint go through the needle more easily, should there be any dried paint left behind. It's also good to help create a little bit of a seal around areas that are screwed together. Lubricant is not necessary for the internal passages of the airbrush as long as the brush is well cleaned and maintained.
Reassemble the airbrush and polish the outside surface with a soft cloth. Do not use oils or soaps on the outer surface of the brush.