You can use common household vinegar to reduce a hard wishbone to a bendable rubbery novelty without degrading the bone. Calcium is the mineral that produces hardness of bone tissue, and the vinegar actually removes the calcium from the bone. Use this activity to demonstrate to your kids the importance of calcium in their diets. While the wishbone won’t magically transform into “real” rubber, it will be very flexible and feel rubbery.
Enjoy a chicken dinner and reserve the wishbone. Remove all of the flesh from the bone. Wash it with warm soapy water and rinse well under cool running water. Allow it to air dry overnight.
Drop the wishbone into a glass jar. Pour enough white vinegar into the jar to cover the wishbone.
Cap the jar to keep as much of the liquid from evaporating as possible. This will prevent your kitchen from soon smelling like vinegar. Set the jar in a cool spot out of direct light for three days.
Check your wishbone once each day. Add more vinegar as needed to keep the wishbone covered.
Take the wishbone out of the jar and pat it dry with a paper towel. Discard the vinegar.
Play and experiment with the rubbery wishbone. Twist it and pull it, then tie it into a knot. Prank your friends by substituting the rubber wishbone for the real one at a social gathering.