Haha just no you don't use a hoover.. you can easily damage a computer with a hoover.
You use an air can to clean a computer, get one and use one and you will understand why.
How dusty is your computer? I have cleaned some old computers and security DVRs which were literally brown with dust which is dead skin, with an air can it took 30-60 seconds to clean. With my computer I just get a antistatic cloth and wipe the bottom of the case, top and sides of PSU, back of GPU as that is facing up and I then wipe front fan filter all once a week.
Go ahead if you want but if you kill your pc don't come crying to us please, use common sense and use an air can.