I had one of the Azteks... and here's what I did.
After finishing painting... spray thinner or cleaner thru it till it flows clear.
Take out the nozzle and drop it in a bottle of cleaner.
Use a pipe cleaner to clean our the air-brush body. If you have more painting to do, put the nozzle back in and blow air thru it to flush it out... OR put in another nozzle to use.
Clean the nozzle by dribbling cleaner thru it while brushing it with an old tooth brush.
Let everything dry.
I did not take the nozzles apart very often -- every 5 - 10 uses.
I used Mineral Spirits for enamel paint, Acryl Cleaner for acrylics, and Lacquer Thinner for lacquer paints.
www.naplak.com/modeling ... a free site for modelers
www.scalehobby.com/forum/index.php ... a nice Modeling Forum