1. Do you use a harness?
N/A.
2. Do you personally know people who do? If yes, are they Frum?
N/A.
3. Have you ever seen anyone use a harness?
No but I have seen the leash bracelet thingy years ago. I only discovered that they actually made harnesses tonight after Googling it.
4. Is this whole thing a joke or serious?
Both.
5. What is a harness anyhow? Never saw one – wouldn’t know what it was if I bumped into it.
Google images may help. IMHO, at least from now on, if it crossed your path, you would recognize it.