Bottles of compressed air are very expensive where I live. While it would be nice and ideal to have and do a "proper" cleaning, I've always used my mouth and lungs to blow air onto the dust so that it twirls around and gets all over the place, just as what happens with compressed air.
Is this bad in any way? Does my breath/air contain something that's bad for the computer somehow? I realize that my method is not sustainable in a professional setting when you are undusting 500 computers in a day, but this is one single computer. My computer.
Is there any reason that I need to buy the expensive cans of compressed air? (And also have to fetch them, besides the pure cost.)