You can put egg shells into your YOLO Compost Tumbler. Egg shells are rich in calcium, which plants use to build strong cell walls. Fast growing vegetables like tomatoes and squash thrive with sufficient calcium in the soil.
Egg shells break down slowly so remember to crush them into small pieces to speed up the composting process. Leave egg shells in the sun for a few hours to dry out, which makes them easier and more pleasant to crush in the palm of your hand.