Since the K&N is oiled, I would think you need to clean off the oily dirt with something petroleum-based, such as kerosene, which might work well, not soap and water, which would be hard-pressed to get that junk off. What is the K&N cleaner like? I've never seen it since I haven't had these filters in long enough to need it. Jack Rich 90 V8Q 88 Corvette convertible 84 4kq