I have used essential oils for nearly everything including internal consumption, external issues, cleaning everything(alternative to bleach, etc), veterinary and can say they work. However, there are a lot of claims out there regarding essential oils that aren't true, so make sure you check a reliable source before you proceed.
Quality is very important, all essential oils are not the same.
It takes a lot of self education to take care of your own health but well worth it in the end.