While I see where it's coming from, I dislike this idea. 5 seconds is such a small amount of time, it'll easily have different interpretations among other players, which will lead to arguing and trouble. Yes, it's not impossible to correctly interpret the passing of 5 seconds afterwards, but it won't be correctly interpreted by everyone I guarantee.
Furthermore, 5 seconds is a bit short to recover a round anyway, as in to do anything proper to a warden, though if it's just 5 seconds to go warden then never mind on this point.