Use 1/2 water and 1/2 vinegar and a few aspirins. The acids in the vinegar force your old skin cells to flake off, much like the store-bought “alpha hydroxy” products. A lot of acne products use salicylic acid, which is basically aspirin with a few small chemical differences. The aspirin won’t completely dissolve, but it doesn’t seem to matter. This works especially well for those big deep acne spots which older people often get.