But if you do talk to someone who really needs all they can get to understand what you are saying, do not speak as rapidly and make sure they can see your mouth. But please do not speak super slow because that is worse, unless it is requested to do so.
If you move your mouth slowly and exaggerated, you pretty much are using only AEILORUWY at which point it is gibberish. Also CDG sound the same, as do MN sort of. So you are not being cool or funny, you are just being annoying.