Originally Posted by 
Plasnart
				 
			Don't laugh, but I  fit a stocking over my snorkel.  Yes a ladies' leg stocking (black of course).  Obviously doesn't filter dust but keeps all objects larger than say a millimetre out of the air box.  Been using them for years after being surprised how many bugs and bits of stick were getting through.  It's a great improvement.  As far as real filtering, I just stick with paper filters and change them out as needed.  They're a consumable like oil filters so I dont sweat it.