G'day all. Some "brand new" air filters for my bike arrived today in the post from eBay. Now, I've not bought this kind of filter before (always had box filters) but the thing is smeared all along the sides in some sort of cruddy greasy stuff. And that stuff is all in the bags and sprinkled on the filters. Before I go and demand a refund, is this some sort of standard goo that get placed on such filters? It's pretty filthy and I'm concerned instead that I've been sold used filters, but reason tells me I've got it wrong, while my gut instinct is not to chuck such filth in my bike.