What kind of “craft” is soaking an egg in vinegar and blue food dye? For that matter, why is an entity called “5-Minute Crafts” pushing a two-day project to make a big blue egg?

They’re all the end products of videos shared by the uber-popular YouTube channel “5-Minute Crafts.” Known for its “life hacks” and “crazy home science tricks,” 5-Minute Crafts ...