We always recommend hand-washing undies in lukewarm water with an extra-gentle lingerie wash. Gently squeeze any water out of fabric, then lay flat on a towel to dry. A detergent meant for lingerie will help elastics last longer. We canâ€™t endorse machine washing, as it will mean that your undies meet their end more quickly, but if you must, make sure you put them in a lingerie bag so the fabric doesnâ€™t get caught on anything. Then line dry. Never, ever put your delicates in the dryer, even on delicate.