What do I do to prevent gossip during a workplace investigation?

What do you do to prevent gossip? In my initial admonishments, we tell people things like, "we'll ask that you maintain a professional level of confidentiality." And I'll often say, "As you can imagine, if gossip starts, it depletes the quality of the investigation that I'm trying to do. And, frankly, I always find out who said it and who started the gossip anyway." And by walking people through what elementary school gossip looked like back in elementary school and remembering that people always know who the story is, a lot of times, it does quelch the buzz. And also just talking about the integrity of the investigation, which includes people in the process and includes them being a participant in quality output. And so that's how I handle preventing gossip in the workplace during a workplace investigation.