Folks have talked about putting a purge as the first "click" in their DPS macro.

Can anyone confirm a) that the logic works and the macro "moves on" if there's nothing on the target to purge and b) post their syntax? Seems like this would be a no brainer to include in all click macro's if this works so that you'll always try to purge if there's something to purge and there's no meaningful DPS/macro hanging concerns.