Just rinse it out, wring it out, and let it dry for at least 6 hours before even thinknig about using it again.

I can't see having to use K&N oil on it...that oil is the active filtering agent on a K&N filter, because the "screen" alone on a K&N does nothing for cleaning the air coming in. A foamy will filter just fine by itslef, I'd imagine the oil would hamper air flow pretty bad and may even damage it?