In recent threads there has been a few diffent release agents mentioned. In fiberglass and other molding work, carnaba wax (Kit car wax not one of the silicones) is very common. I suspect that the shoe polish is wax based. I've used Kit on various things and had good luck by using 2-3 coats and buffing to a shine. Since there are probably some here who shine their car more than their shoes this is one more tool in the box.

This has been a great forum for me. Thanks for all of the info gathered here.