This is the type of idea that sounds good when you first hear it, then it falls apart upon further questioning. Here's how it goes: "You know how you sometimes don't have utensils when you're at work, but you always have pens? What if the pen caps were the utensils?" / "Wow, that sounds really useful. Wait a minute, where do you keep the caps? Wouldn't they get dirty? And I lose pens all the time. What if I lose them? How many of these do I have to buy? Who are you? Why are you in my house?"
As you can see, this is theoretically good, but not in actuality. Just keep fresh utensils in your desk like I used to. And by fresh I mean that I never washed them and they got me sick repeatedly.