cleaning a airbrush

Usually what I do is i spray thinner through at a high PSI until it runs clear, i then take the needle out and wipe it down and lube it then replace it and spray some thinner through again ! this usually gets it nice and clean!

its like the Badger 300 a external mix

First of all, welcome to the forum.

Could you be more specific, what kind of airbrush is it? external mix?

Most airbrushes need to be disassembled to be cleaned properly. Use Q-tips to clean with the apropriate thinner.