A Question about Cleaning Aftermarket Air Filters....

[Rosco]

I have an Injen intake on my KA right now and I currently use the K&N air filter cleaner on it. I don't know if this is the proper thing to use on it, but on Injen's site they say that the air filter is reuseable. They don't tell or offer any product to clean it with so I figure that the K&N kit should be fine. Is this okay? Also I was talking to a guy that works at Advanced Auto Retards inc...(I give it this name due to someone who works there who is a complete ignoramus..lol) and told him how I always run outta the air filter oil. He said that "Marvel Mystery Oil" is basically the same thing and that it was safe to use on reuseable cotton air filters....Is this true?