buy Swifter sheets that are used for a Swifter and cut out pieces of sheets to fit your air intakes for all your fans.
I would think another filtering media might be better suited for this. Swiffers are very dense and would cause
enormous airflow restriction. What you gain in cleanliness, you loose in capacity to keep things cool...which is the whole point.
Plus the added stress to the fans, which will attempt to maintain a certain rpm based on their purpose and make(in some cases, heat load). Without enough
air to move, the blades effectively become a braking system. Destroying the very weak little motor in the fan.
I'll put an anemometer on one of the extra case fans I have around with a sheet of swiffer on it this weekend and report back.
In the meantime, I would suggest something along the lines of those cheap 1/4" cut-to-size foam filters from Ace Hardware before
a swiffer pad...if anything at all.