DECLUTTERING HAS BECOME an industry in itself in recent years, with Hoarders prompting TV viewers to recoil in shock at the sight of dwellings stacked to the brim with stuff and Marie Kondo teaching readers The Life-Changing Magic of Tidying Up. Let there never be a doubt that a buck can be made off human slovenliness. But even with this glut there’s a place for The Gentle Art of Swedish Death Cleaning, the new Peacock series based on Margareta Magnusson’s book of the same name.