For more than watching silly videos. For instance, my car headlights were getting that dingy yellow glaze on them and looking pretty faded and nasty. So I looked around at the local auto zone for a fix and was told to get a certain kit (for $24) and use it to clean the lens. The problem, though, was twofold. First, I own no drill (which was needed to run the circular cleaning attachment) and second, I’m far too cheap to spend $24 on anything but a book.
So I looked around on YouTube for a video on how to clean a headlamp lens. And I found one- recommending toothpaste and a towel. So I figured, what have I got to lose but a little toothpaste, right? And boy, did it work. I didn’t snap a before photo but here’s the after-
I expect now I’ll actually be able to see victims of nighttime drive by baptisms! Thanks YouTube, for having something on besides cats.

Hey, you mean, my father was right???
He must as per the video, because when I was still a little boy, he would tell us to shine the white pottery in the bathroom and even metal in our furniture, with toothpaste! I thought he was crazy thinking that pottery and metal could develop cavities, but, now I know… he was right!