Vinegar is an amazing product.
For insect bites, I mix about half with water and add an essential oil, Peppermint or Spearmint, about a quarter teaspoon to the cup of vinegar/water.
For bee stings I have always found that teaspoon of baking soda and vinegar immediately kills the sting. I put a bit of baking soda in my hand, pour some vinegar in it and as it bubbles, slap it on the sting - I was always the one the kids who had bee stings came running to - I carried a prescription bottle with baking soda and an old vanilla bottle with vinegar in my first aid kit.