Instead of using your index finger, use a fork or spoon to push a piece of bread into the peanut butter jar. As peanut butter is oily, another idea will be to pur some warm water into the jar, swirl the water around its inside and then figure out what you can cook with it. For the lazy way out, go to yummly to make discoveries.
You can make cocktail from peanut butter when you have about 4 teaspoons left in the jar. This Russian recipe is a grown up version of a peanut butter milkshake. Instead of water, you use a mixture of vodka, Kahlua and low-fat milk to stir out every bit of peanut butter in the jar :)
This Chocolate Peanut Butter Protein Shake just need 1 tablespoon of
peanut butter. You can use 1 cup skim milk required in the recipe to clean up the jar.
You can do a search for "peanut butter" on
yummly to discover more recipes. My suggestion is that you keep the old jar and open up a new jar of peanut butter to create any recipes that requires some liquid ingredients. Use that to swirl around the jar to clean up any leftover residues. Other than Yummly, you can also google "add peanut butter". By doing that, I found this link:
33 Ways to Use Peanut Butter