Layering deodorant
You may use this technique with dry shampoo and possibly mascara, but a fresh layer of deodorant won’t keep you fresh if it’s sitting on top of yesterday’s stench. You need to apply product to clean, dry skin, so it can adhere directly to the surface. If layered on top of an older product (especially a thick cream or solid) it’s likely to be less effective, explains Dr. Plotner.