I saw a book on the life of Israel Oddeser, [the person that found the hidden letter of Rav Nachman concerning  Na Nach Nachma Nachman Me'Uman] and I noticed he told one person about the importance of olive oil -both for putting on a wound or sore and also to drink a little bit. There he also mentions to put on a wound a sort of concoction made of tea. [That is to boil tea leaves in a small amount of water so the water is like a concentrated mix, sort of like concentrated orange juice.]