OK, first off, Air Duster is not a regular cleaning product. It's not used for stains or spills. You use it to clean things like crumbs from under the keys of a laptop. Or dust from the fans of a computer.
It comes in a silver bottle that is so cold that precipitate forms. You have to put a small straw into the nozzle to concentrate its aim somewhere. From then on, it's just like spraying at something.
It gets the crumbs from my keyboard out fairly easily. They just blow right out of the cracks under the keys. I even used it to clea the dust from the fans of my laptop.The dust just blew away very easily, though I have no idea if the dust went inside the laptop or in the air. Probably not good to have to settle inside the laptop though. It can make your laptop overheat pretty easily.
Anyway, this product was really great to use. I had fun aiming it at things and having the air inside just blow it away. I don't know what's so fun, but it is! Hard to explain. But it's very useful!