The SILVADUR in the wicking fabric ensures that the panties don't smell. If you're worried, give them an extra quick rinse on cold. Weirdly, you shouldn't use a vinegar rinse as this can affect the leakproof layer. The same goes for Soda Ash or Soda crystals. If you're really wanting a natural solution, look at using something like SoPure's Lingerie Laundry wash, which is locally made.