Just thought I'd pass this on. Without getting into the light vs no light tactical discussion, I like to leave my Streamlight TLR mounted on the rail when I shoot my HD pistol. Well, I was starting to get irritated at the dulling of the lens from muzzle gas because the light sticks out about 1/4" past the barrel of my P30L. Nothing I was using would get it clean until I found a tip to try polishing it using a clean pencil eraser. Holy cow, it worked like a champ. Hope this helps if anyone has run across the same thing.
I used a plain ol' pink eraser on the end of a No.2 pencil.