@Kiley5 A lot of guests and people in general, would think "Yadda yadda, a plate is a plate, what a control freak, what does it matter which one I eat off of as long as I wash it". So they'll nod, but ignore what you've told them because they think it's no big deal, instead of thinking, "Well, it seems silly to me, but it's her home and I need to respect her wishes". So as others have said, things you really don't want them to use are best secured in a locked cupboard. And rather than having them wonder what's so special that you've locked it up (guests have been known to get into locked spaces, lots of people are nosy and curious) just casually mention that you locked that one cupboard because guests got confused about which dishes were yours and which were for guests.
It's so obvious to us what is what in our own homes- you know what your dishes look like, and you know what the dishes you bought for your guests look like, but all those dishes are unfamiliar to a guest and paying attention to such things after a long journey can be overtaxing. Also many people just aren't observant and don't have an eye for detail. I've had friends stay with me for 3 weeks or a month and still don't observe that I keep my plates on this shelf and my bowls on the other. I'll end up constantly searching for things, finding them in the oddest places, and this is with friends staying who respect me, not even guests. Which is a pet peeve of mine, wasting time looking for things.