For insect bites dab on malt vinegar or hold the cut side of half an onion against the stings.
For salad dressings, you can use most types of vinegar with the exception of malt vinegar.
The type of vinegar you use is not necessarily important - there are many different types available on the market, but the most common types used in toenail fungus treatment are typically regular malt vinegar and apple cider vinegar.