How do you get smudges from body oils, etc off the fiberglass barrel?

My hands are rather oily, and I was shocked at a pen show to see a new Lamy 2000: the finish seemed so dull, so drab. My 2000 has gained a shine.

I don't think anything but mild soap and water will get oil out of a L2K barrel. Your pen may have begun a journey of transformation...