I've never used compressed air on my computers. Never needed it and I clean them out of dust quite regularly.
I use an air rocket though which I bought for cleaning dust off camera lenses.
It's a set of rubber bellows that squirts air wherever you want it. Far more environmentally friendly, and cheaper too because you only need to buy it once. And you don't risk getting propellant all over your sensitive components. While I am doing that I suck up the air around it with a vacuum cleaner. I also don't have to worry about the vacuum cleaner creating any static electricity and discharging into the sensitive electronics.
I use an air rocket though which I bought for cleaning dust off camera lenses.
It's a set of rubber bellows that squirts air wherever you want it. Far more environmentally friendly, and cheaper too because you only need to buy it once. And you don't risk getting propellant all over your sensitive components. While I am doing that I suck up the air around it with a vacuum cleaner. I also don't have to worry about the vacuum cleaner creating any static electricity and discharging into the sensitive electronics.