Yes you would have to cordon off the areas, but it should only need 40 mins to an hour and its fine for re-entry. You could spray but it wouldn't be as effective, and certain items would need further cleaning, even with fogging. Do the management only want to be seen to be addressing the problem or are they serious about the threat? If they are serious then it would be worth a fog in my eyes, unless you drench the reception with your gloria that is!
Its Danny by the way!