This might seem like a pain but to ensure the longest life from your engine it's a must !
Before getting started you will need some items to assist you in cleaning your air filter, These are the things i use and work for me you can use what ever suits you .
1. 3 Coffee can's
2. 1 Gallon of Mineral Spirits
3. Clean rags and a clean work area
4. Liquid laundry detergent
5. Air filter oil of your choice
Before you remove your air filter take the time to vacuum out as much dirt, dust ect. from your air box then remove your air filter taking care not to get any dirt or dust down stream of the filter look past the filter with a flashlight if you see any dirt then your filter was not oiled or sealed properly and you will need to remove the rubber boot between the air box and carb to thoroughly clean it
Fill the first coffee can with enough mineral spirits to roll the filter around in . This will remove most of the dirt and filter oil, drain the filter thoroughly then repeat this process in the other 2 coffee cans using new mineral spirits each time, By time you washed it for the 3rd time you will have removed 90% of the filter oil and dirt . Now let the filter dry over night until thoroughly dry, Then its time to finish washing with liquid laundry detergent use lots of soap and water give it a good massage but be careful not to damage the filter rinse from the inside out making sure you get all the soap out. Now let the filter dry preferably over night
Now comes time for the real mess putting the oil on the filter, Don't be afraid to get your hands dirty when doing this and follow the manufactures instructions.
Things you don't want to do: Leave dust or dirt in the air box or after the filter, Leave filter oil on the sealing surface of the filter (The filter will slip off no matter how much you tighten the hose clamp) Don't take any short cuts the life of your engine depends on it.
I have 3 filters for my pilot and keep the clean ones in a 1 gallon ziploc bag's ready to use.