I have bought the K&N cleaning kits before and they work fine. But what I'm wondering is if I can just use some 409 if I already have the filter oil. I mean 409 smells and feels just like the cleaner they give you in the kit. I have to clean my filter OFTEN and if I can save $10 a month by just buying the filter oil separate, a dollar saved is a dollar earned, especially in college. Any other tips?