I use the PJ1 filter cleaner and oil. The cleaner really works well and gets all the dirt out.
What I do is spray it down good with the cleaner, and let it soak a few minutes. Then rinse it out with a hose from the inside out.
Then I have a tub with warm water and Dawn dish soap and I dip it in that and squeeze and work it into the filter good. Then rinse and repeat two more times with the dishsoap water.
Then let it dry really well, I usually let it dry overnight. You want to make sure it completely dries or the water will displace the oil in areas, letting dirt in. Then your ready to oil.
I run a K&N filter on my Shee now, but that's how I use to clean it, and still do with my other quad and my wife's quad. I take filter cleaning/oiling very serious..... the lifespan of the engine depends on it.