Utensils

Question

If you go to a catered event (not at a restaurant) and they have a kosher meal for you, but no silverware, are you permitted to use the regular silverware on the assumption that they haven't been used for 24 hours? I assume that if the even was at a restaurant you would not be able to use them, because here it is almost certain that they were used in the previous day? Am I correct in this assumption?