I use the same cleanup method that I use for acrylic paints
I keep a paint jar full of 50% hot water and 50% Windex. Spray it through the airbrush into a soda bottle, wipe the tip off with a Q-tip dipped in the Windex mixture, wipe out the paint cup too and call it a day.
Once in a while take it all apart and wipe the parts down with Lacquer thinner.