When I was reading the article I thought - was somebody watching me last night? Because I went through exactly the same thing. And came to the same conclusion, easier and faster to create a temporary new table than deleting directly with a sub-query.
It's interesting how kids can adapt so naturally. We've got so many preconceived ideas about difficulties.
When I was young there was a deaf kid in our school. We just figured out communication as needed. Kids don't overthink things like adults do. The environment matters, but sometimes we should just let kids figure it out.