Cut the vanilla beans in half; then slice the halves down the center so the little beans inside are exposed. No need to slice all the way through—just enough to allow the vanilla beans to escape the pod. Place 5 vanilla bean halves in each pint jar.
Pour enough rum or vodka into a pint jar to leave a 1-inch head space at the top. Cut a piece of wax paper to place over the tops. Screw on a lid and shake up. Shake once a day for the first month, then once a week for four months, then once a month for the remaining time. Store out of direct sunlight.