I think where the confusion comes in is that, at least in the English translation of the book, there is a lot of mixed messaging. The general narrative arc of the chapter on books was, "Sure, if you really love books, I guess you can own a lot of them, but let me now spend 5 pages browbeating you with exposition on how you can't
really love more than a handful of books at a time, and talk at length about how how my life was greatly improved by throwing my favorite book, the one book that has brought me the most happiness in life, into the trash."
That said, I'm pretty sure there's nowhere in the book where it said that a 4,096Hz tuning fork - that's the perfect frequency for sparking joy - can't possibly spark joy.
On the other hand, that laptop computer brush. . . I imagine the woman who wrote The Life-Changing Magic of Tidying Up, the book that argues forcefully that the only good container is either made of cheap clear plastic or an old shoebox, would have advocated for dusting your laptop off with a cleaning rag.
On the other other hand, the woman who wrote that book wasn't a world-famous figure with her own popular series on Netflix.