Wasp venom is very alkaline and vinegar is an acid that helps to neutralize the venom, notes Mother Earth Living. However, wasp venom does contain many different components that cause pain and cell death, so vinegar alone will not completely relieve the sting.
Wasp venom contains some alkaline ingredients, which can be neutralized with an acid like vinegar. Those who have been stung may try soaking the skin after removing any stingers and washing the area with soap and water. Some, such as Twin Eagles Wilderness School, recommend a mix of baking soda and vinegar to help draw out any excess venom from the skin. However, wasps inject the venom under the skin and diffuses into the skin tissues, so it is unlikely that much vinegar will reach the venom to neutralize it, notes Compound Interest.
More traditional treatments for a wasp sting are to take an anti-inflammatory, such as Ibuprofen or Aspirin. This can take a little while to kick in, but will help keep the inflammation from getting worse and reduce pain. Those who are stung may also apply a topical antihistamine cream like Benadryl to the sting. This topical helps reduce inflammation, itching and irritation by neutralizing histamines found in the venom and released by the body.