I can't respond to ingesting TTO, but I do know it can be an irritant when applied topically. After using it to rid myself of a wart, I compounded my problem by developing dermatitis around the wart area -- blisters, rash, itching -- for two weeks. Apparently, a small part of the population reacts to TTO in this way.
(My reaction may be due to having candida overgrowth, which makes one more susceptible to chemicals.)
To test any essential oil: apply a small dot of oil to the inside of the upper arm, wait 24 hours. If there is no reaction, you can safely use it.
Many essential oils need to be first diluted with a carrier oil, like almond or coconut.