Toothpaste to repair cracks

I had cracks on my Samsung screens few months ago. No big cracks but still. I realized, looking at on-line forums, that it was possible to use toothpaste to fix them. I followed a Youtube video that showed the approach : I dabbed a bit of toothpaste onto the end of a Q-tip, that I rubbed in circular motions on the screen until the scratch went away. I then wiped it with a slightly wet tissue to remove the rest of the toothpaste. It only works with non-gel toothpaste.