“Squishy and smooth, kids and adults alike will love the soothing sensory experience of Orbeez!” Spin Master Ltd., the company behind Orbeez, explains on its website. “There’s no limit to the ways you can play. Explode them, squish them, squeeze them, bounce them, crush them or let them flow through your hands! Use your imagination and have endless amounts of fun with Orbeez!” The official description sounds innocuous enough. But the polymer beads also play a central role in a viral social media trend popular among teens and have caused serious injuries across the country. The so-called Orbeez Challenge—which may...