But instead of gross-out shock value, think of why it's important. If you really care about your brushes — and want them to last and perform to their fullest potential — then don’t you want to keep them well-maintained? Don’t you want to treat them as kindly as possible so they stay in tip-top shape, even after months (or even years) of use? If your answer is a resounding yes, then it’s time to start combing them. Yes, you read that right.