This old-fashioned laundry product is the secret to bright white clothing and linens. Getty Images / Cris Cantón When it comes to laundry products, new stain-treating and odor-eliminating products tend to get all the attention. But it can be worth revisiting vintage housekeeping formulas and methods that have fallen out of fashion—like laundry bluing. Laundry bluing is a product that is used...