should I seperate

Hi i have been told to get a water spray with vineger and water in and spray all the chooks  when they are roosting, as this will mean they all smell the same, when introducing hens back with others, i do this any time i introduce a new hen, or one that has been pecked, it seems to work, or maybe i have just been lucky, and although i haven't done it, as not needed to i was told by the same chicken breeder to spray the pecked hen with iodine, as they don't like the taste or the colour!!!!!!