K&N has a kit for cleaning and re-oiling their air filters. You should be able to find it at an auto parts store, Amazon or Wlamart. Here's a link to the K&N product - https://www.knfilters.com/99-5…-care-service-kit-aerosol. K&N shows an MSRP or $20, but I've seen it for as low as $14 +/-.
Before I added my Hahn turbo kit, I had a Hahn CAI. Personally, I think the difference in sound from the CAI plays a psychological role in making the CAI feel like it's making a difference. Just my opinion, since I never dyno'd it.