... the interior surface. 2) Take the cap off again and, leaving the vinegar ... interior surfaces with the brush. Next, take the brush out and replace the cap. Shake ... on a soft cloth. Wipe down the outside of the bottle with vinegar; then, rinse under water. 4) Wash the cap with ... a clean, vinegar-soaked cloth. If the cap smelled musty before you began cleaning, let the vinegar remain on the cap ...