Brogan Ingram isn’t a cleaner by trade. But never mind that. Her cleaning videos have landed her 7 million social media followers and lucrative partnerships with major companies such as Scrub Daddy.

Jo, the director of Hoarder Clean Up UK, is spending the morning in this semidetached home in a southeast London suburb. Her client, Emily, a pseudonym, is a woman in her mid-30s who asked that her ...