Yup when I was new to paintball and thermals were first released I made the mistake of using cleaner on the inside of the lens (not knowing any better) completely borked them it did
JT spray works spot on... although I'm still sure its fairy washing up liquid and water repackaged and sold for an extortinate price
why don't you just use water?!?!?! it cleans the best and it doesn't harm inside or outside as long as you don't pour water onto the inner lense... it's what the bits of paper say to use as well. Save yourself some money....or i'm just a cheap skate
no don't submerge it dude. run water on the outside of the lens with it pointing downwards and then get a tissue dampen it and then rinse it out and wipe the lense. then clean the edges and your done.