a716 -
First off, welcom to the fora! (I'm told that's the proper plural of "forum.")
I know nothing about that light in particular, but I do know quite a bit about other reflectors that are popular around here. And my advice is don't touch it with anything! If it is coated the same way the Pelcan, Surefire, and many others are coated, you can do nothing but ruin it by "cleaning" it. Use compressed air ONLY. Do NOT touch it with anything, or my experience says you'll be sorry. Some minor dust won't be nearly as annoying as destroying the entire reflective surface!