Cleaned mine... mine was filthy after 15k miles. Yes I'm using K&N Typhoon. Just purchased CRC can and sprayed it... take seconds and it's now sparkling clean. I didn't reset my ECU, but I'm gonna do that after I clean my K&N Filter as well.
It won't hurt you as long as you are careful with it. I felt less hesitation and felt smoother idle after I cleaned it. Mine was BLACK on one side.