Pay attention to the compatibility list though. If you use the Clothâ„¢ on an iPhone 4 or earlier then you're in uncharted territory, who knows what could happen.
I thought the same. I had no idea there was a special cloth in the box. I'll have to dig it up and search for it. It sounds like a quality microfiber cloth is still fine though.
https://www.apple.com/shop/product/mw693am/a/polishing-cloth