What did the Babylonian captivity do to the Jews' idolatry?
The Babylonian captivity cured the Jews of idolatry once and for all. This was one of two things that happened to them during those seventy years. Afterward they might be agnostic or atheistic, but they would not worship idols or Oriental religions.
Les explains that during the seventy years in Babylon, two things happened to the Jew. First, they were cured once and for all of idolatry. A Jew may be anything but orthodox, but he will never be in idolatry. You do not find a Jew worshiping Oriental religions; they may be agnostic or claim to be atheists, but they are not idolaters. Second, they found out they had an acumen for business, and Babylon was the source of the whole system of banking.