Food for thought...
I havent seen it posted here (my search skills are lacking) but I dont think anyone has ever mentioned the need to clean the GUNK off of the Millenium series lights after firing a few hundred rounds. I noticed that when the light is mounted closer to the end of a shorter barrel (14.5 & less) that the lense gets nice coat of junk that is difficult to clean with spit (my favorite and the most unsanitary cleaning fluid).
When you mount your lights, you need to be aware of this minor inconvenience. BTW - anyone else have this problem?

Have you tried warm water and an old toothbrush ?

Since I wear glasses and I'm anal about clean lenses I buy liquid cleaner in a spray bottle at wally world. Works great. If your lens is lexan you might want to clean it wet so there is less chance of getting scratches on it.

I guess that saliva isnt all that effective - but in a pinch - it kind of works.

Havent tried the toothbrush but the only field expedient one I have is in cleaning kit with CLP over it. Next run to PX...

I havent tried wally world solution - just some govt issue windex (some generic manufacturer that uses blind people - the irony).

The Surefire solution is probably worth a phone call - when its ready.

I guess I was just ranting because its hard enough cleaning my weapon - let alone the flashlight lenses...

Tissue or lense cloth? Cleaning patches have worked for me in the past too.

I don't know that I want anything on the lense that will leave any residue on it. Thoes lamps give off enough heat to heat the lense/bezel consiberably.

If you use a tooth brush, you had better only use it on optic lenses. If you're using the one that you use to clean gun parts, you're probably doing more damage then good.
I would recommend using a silk bag that quality sun glasses come in to wipe down the lens with. The liquids mentioned above would also work well. You want something soft to rub glass/plastics with.
-Steve