Gents -
Sorry, have to disagree, but with a caveat. Caveat first, I only use MM acrylics, no enamals, no lacquers. I've never taken a nozzle apart, and have some that are 15 - 20 years old, whenever Testors first came out with the Model Master line of airbrushes, pre-Aztek. (Still have and use the same air brush too.) I just do an external cleaning with the tool provided. I do keep the nozzles in a sealed container of water. I've been told that's not a good idea, either, but it hasn't really hurt them much.
Still working fine, so if you need to take them apart, it's your call. If after 20 years, I have to spring for a new nozzle, I can probably afford that, :D.
Archer out.