My impression is that this rabbi is very popular. He seems very sincere and k'shmo kein hu, humble. But I don't like the approach. Tzeniyus is not important because men might sin by looking at an un'tzeniyus woman. Tzeniyus is important because it is a manifestation of Hatznei'a leches im Hashem Elokecha. As in Micha's Ma Hashem Elokecha mevakesh.