I'm sure I've read and heard of people waxing hardwood floors with paste wax and buffing until they were blue in the face.
In fact, my mom used to tell us about how she'd put on old thick socks and "skate" to wax the floors when she was a teenager!
The Renewal box specifically mentions waxed hardwood floors, too.
Well, if it isn't wax, but some other finish, will a 'wash' with mineral spirits before using the Renewal cause irreparable damage to the floors? Mineral spirits are recommended by Flecto for precleaning waxed floors before using the product.