Just so you understand.  I was not kidding.  My leaf blower has a wind velocity of 300MPH (on high speed).  It does a really good job of cleaning out a computer case.  And it does it in seconds.
I typically will tape the fans down, and for the PS fan, I just push a pull tie through the grill to hold it in place.
I do admit, when the neighbors see me doing it, they really get a funny look on thier faces.  Dunt know why.