I just think you have to be extremely cool to get away with licking your finger/thumb to count your money or turn a page.
And by "extremely" cool, I mean EXTREMELY cool. Like Shaft-type cool.
Or maybe extremely angry-looking, like Mystikal. *daydreams*
Yeah, if you can lick your finger/thumb in a really angry or extremely cool way, I guess it might not be suspect. But... no guarantees.