1. Clean with mild dish soap without soaking it.
2. Sprinkle a generous amount of baking soda inside the bag and over the stained area. Let it sit for at least 24 hours—baking soda absorbs odors like a champ. If the smell’s really bad (like if it was milk or beer), you might need to leave it for 48 hours. Shake out the powder afterward.
3. Vinegar for Stubborn Smells: If baking soda doesn’t fully do the trick, mix equal parts white vinegar and water in a spray bottle. Lightly mist the inside of the bag (don’t drench it) and let it air out in a well-ventilated spot. Vinegar neutralizes odors, but it’ll smell like vinegar for a bit until it dries completely.
4. Handwash if needed and be sure to remove all soap and then dry in sunlight (sunlight kills some bacteria caused odors too).
5. Charcoal or Kitty Litter (Optional): If the smell lingers after all that, toss a small pouch of activated charcoal or unscented kitty litter inside the bag and leave it sealed in a plastic bag for a couple of days. Both are great at absorbing stubborn odors.

Check label to make sure the bag does not say to never use water or vinegar. Also, make sure not to use any harsh chemicals like bleach.

Good luck!