Back when I was an Episcopalian altar boy, some of the manuals for altar boys prescribed polishing the soles of one's shoes since they would be very visible to the congregation. I seem to have the notion that the soles of formal shoes should be blackened. Otherwise I have never heard of putting polish or dressing on soles. An exception would be edge dressing, such as Allen Edmonds sells, that I put on the visible edges of my leather-soled shoes. Concerning putting oil on the soles of the shoes, wouldn't there be a danger that that would soften them, making them kind of "punky," hence more prone to damage or abrasion?