wash with simple green and use k&n spray oil-have been doing this for along time with excellent results-2 strokes -4 strokes no problems. I had a K&N in my last truck. I cleaned it once using the K&N filter cleaner and that stuff worked really good on the K&N filter. I wonder if it would damage a non K&N filter? I still have the cleaning/oil kit. May have to try it out. No-Toil is still the way to go. I hear that Twin Air has a product that is very similar to No-Toil. Twin Air also told me that No-Toil will work with their air filters. I am testing that out right now. May have to give the new Twin Air oil and cleaner a try as well.