Lay ginger slices out on your dehydrator tray. Dry according to manufacturer's instructions, rotating every 20 to 30 minutes, until crisp and fragrant, about 2 hours.
Break up dried ginger into smaller pieces; transfer to a saucepan. Add coconut oil; heat gently over low heat until natural oils from ginger infuse the oil, at least 2 hours.
Strain ginger oil through a strainer to remove large pieces. Wrap cheesecloth over top of a glass jar. Pour ginger oil through cheesecloth into jar to strain again.