My Japanese wife says that she never really spoke anything while she was practicing kanji, and I don't even know how you'd be sounding out characters as you write them because an individual character can have very many strokes that aren't phonetic at all, plus an individual Kanji can have many many pronunciations; so trying to "sound out" Kanji doesn't really make any sense from the start. I think this article's description of Japanese education is probably inaccurate.