I cannot give you any advice for using Essential Oils for medical or transplant purposes.
However, personally I do dabble in the use of oils in my own home. There are therapeutic grade oils. From what I have learned so far- there are lots of different grades of oils, distilling processes and ways to use oils. Essential Oils are really popular right now but I have read quite a few stories on people not using them correctly. Some oils are very potent and need to be used with a carrier oil or will burn your skin, some shouldn't be blended together, some shouldn't be put on the skin at all, some can be diffused into the air. I have to stress how important it is to do your research and know what you are using before using, applying or diffusing. I hope this helps a little. I will say using lavender at night for relaxation and peaceful sleep has become a regimen in our house. Good luck with your research!