Recently, I’ve instituted this methodology at home, too. Having twins means often one will interrupt the other’s reading by blurting out a word which the latter may be stuck on but which the former knows. Now I just explain to them that in order to become good readers, people have to struggle with new words and think about them, sometimes with a little coaching (“sound it out”, “read the whole sentence to see what word would make sense there”, “check the pictures for clues”, etc.) if they so choose.
Coaching or Time has greatly improved the quality of life in our home when it comes to reading with the kids!