K&N filters need to be oiled to trap dust.  The oil in't great smelling, and as with any petrochemical, isn't good for you to breathe.  I guess you could use it dry and see if it does anything, but they really do rely heavily on the oil to "stick" the fine particles to the gauze.  Without the oil, the dust will come right through.  I'm with Alan, use furnace filter material, maybe even the HEPA type.  The $ they get for them seems expensive as a furnace filter, but when you figure you can cut 4-6 G filters out of one, it's a lot cheaper than the factory ones.

Also if you search on "wiper" in the BenzWorld forum with me as the author you'll find a thread where I detailed some improvements to the wiper shafts to prevent your new ones from rusting or wearing out by providing a method to grease them from the outside periodically.

-Dave G.