Mine was full of dead bugs and other crap. I ended up gutting it and using a dry element so I could keep the look of an oil bath. http://farm7.staticflickr.com/6236/6286050234_968eb64773_z.jpg

I'll probably switch to the K&N they're using in the post you linked to once the cheap paper one I'm using reaches the end of its life. Its a cheapie Specter brand from Autozone and its supported by a rubber sleeve I picked up from the plumbing section of Home Depot.