Windex is nothing but simple detergent and methanol, diluted in water. And, of course, that blue dye. If you spray it on a cleaning cloth, I don't see how it could harm anything. It does the job on grimy finger prints, but is mild enough to not harm finishes on products.
Formula 409 contained much harsher detergents and solvents. As originally made, it was a commercial solvent and degreaser meant for industries with particularly difficult cleaning problems. The brand name still exists, but that original 409 might not be sold anymore.