Stained fingernails are a common problem for every woman who is working in the kitchen. But wearing a transparent nail paint all the time is not a healthy option as well. I usually get rid of stained nails by dipping them in bleach water mixed with lemon juice and then rubbing them with a nail buffer. Rubbing nails with a bath salt and dipping them in hot water also helps! Try cleaning them immediately after you're done with kitchen, so that stains do not become lasting.