All his days they departed not - This must be understood in the letter rather than in the spirit. There was no open idolatry in the reign of Josiah, but the reformation was seeming rather than real, superficial rather than searching and complete (compare the marginal reference).
Related Commentaries of 2 Chronicles 34:33
2 Chronicles 34:33
33 And Josiah took away all the abominations out of all the countries that pertained to the children of Israel, and made all that were presentj in Israel to serve, even to serve the LORD their God. And all his days they departed not from following the LORD, the God of their fathers.