Some K&N fit poorly, that's another source of dirt. The urethane frame is hard as heck.
One way to keep the oil mist down is to wrap the filter in pantyhose. It also makes the filter easier to service since bugs and big dirt get caught out. You could jsut remove the pantyhose 1/2 way through the service interval, with the dirt and oil and use the filter a bit longer or clean it.
IMO, it's a worthless mod except some vehicles have very small filters, that more flow MIGHT help, but basicly once flow is adequate, more does nothing. It's like the difference sucking air through an old vacuum bag verses a new one. The difference being that 1/1000th of a HP difference in the actual force needed for SUCKING through the media. That is basicly nothing, in my book.