i use the big and second biggest air holes most often.
Me too!
I have to say, so far my mini nautilus have been excellent. However, I haven't gone far with one... not even to Sainsbury's...
I have had a few moments at home, but nothing that doesn't go away after a few good puffs. How much power have you got to play with?
Mostly, if it's a bit wet, I blast it at high power for a few goes.
What battery/mod have you got?