An interesting question and one I've been asking myself, as a newbie, why don't airsofters wear cam cream, if, and most do, go to extraordinary effort and lengths in acquiring and collecting their loadouts?
Granted, it's not the nicest thing to ear, but neither is a helmet or body armour when it gets hot and sweaty. Baby wipes are good, but the best thing is good old fashioned soap and water!!
Given the effort and some of the looks people go to, I would have thought that a few minutes going for an "alley" bit of cam cream would complete the look?
In terms of being spotted? Well a white face will stick out like a bulldog's proverbials at the back of a darkened room, in a woodland environment, movement will get you seen, first time every time, after that, its' anything unnatural that doesn't blend in.
Clearly there's no point if you're wearing a full face mask.
Just surprised that given the open and unjudgmental nature of this sport, this is a contentious issue.