@Natasha_Jay this has been debunked so many times.
It was just right for people in Japan. it does not work well with the regular pencils from US or EU markets. those BIG branded ballpoint pens worked a lot better. YMMV.
https://www.youtube.com/watch?v=vaSN4J3a_60
@adorfer @Natasha_Jay it does work with regular pencils in Europe.