Internal use of Hydrosols. If you do the only caveat is to ensure you are using true hydrosols. The 'floral waters' available from most online retailers are water with EOs dispersed with PEG40 or a similar chemical. PEG40 is not good taken internally through currently acceptable in cosmetics. So research the PEG40 before you go this route.
We market organic hydrosols which is the distillation water from the steam distillation of EOs as you know. The thing to watch here is that they have been correctly filtered and are fresh season. The best time to pick these up are in the autumn after the distillations. These are the true hydrosols written about and used by Suzanne Catty and Len Price/Katherine Svoboda. The reason wholesalers market 'floral waters' is the tru hydrosols have limited shelf life and must be refrigerated. Who wants to go to that trouble when you can add some EO to water and ship it? The difference is you miss out on the water soluble components which Catty and Price is writing about.
Of course you can make your own with an alembic (Jeanne Rose) and drink the water which takes you neatly back to the days of Culpepper. This was the process he mostly talks and writes about. Though many steam distilled oils (chemical oils as he called them) were available to him (60 EOs were in German pharmacopia in the 1600s. This was the scientific frontier and so being studied at Cambridge when Culpepper was there I imagine) However chemical oils were expensive and Culpepper mostly worked with 'hydrodistilled' herbs in an alembic for his patients taken as a water internally as I understand it. A shame Culpepper died at 38. Who knows where this might have gone. So yes we are back to the future here!!
CO2 process oils as food additives. The only thing I hesitate about the Germany sourced Co2 oils is the distance from where many Eos are grown. The steam distillation is a better field technique as I understand it though some distillers eg the Rose Otto (see writeups on Bulgaria) are putting in Co2 apparatus alongside their hydrodistillation units. The Indian Co2 is gaining attention and a big EU project is about to start in this area of technology transfer through the Aromatherapy Trades Council which I might get involved in but my concern is finding a reliable counterparty as I have little experience of dealing direct with India. Those who do rave about the quality and Co2 oils I imagine are harder to fake the aroma being closer to that of the plant. I do like the absolutes and I suppose the test is that the perfume companies do not use the Co2 oils but prefer the absolutes. A gap there for the artisanal perfumiers perhaps!!
Internal use generally. Internal use is only to be considered by qualified aromatherapists under the supervision of a clients doctor or nurse. Its important to get through the stomach in a capsule if dosing internally in significant amounts and if the target is the intestines too. If a liver cleanse or impact on the liver enzymes is the objective then taking orally makes sense as the stomache/intestine contents go direct to the liver. You would look to other routes if you were aiming to bypass the liver eg if you were wanting to bring antibacterial or stimulating properties to bear on the lymph or muscular system (why external application massage/compresses is such an effective technique). EO constituents + stomach acids what could possibly go wrong!! My concern would be the hydrochloric acid. In general though Alcohol + Acid = Ester + Water so actually the mucosa irritation issue aside or liver overload concern (depleting enzymes like Glucuronic acid - the Koala trick for munching on Eucalyptus) there shouldnt be (other than the HCl) great cause for concern in principle. Aromatherapists love esters.
Organic Hydrolats listing
Organic Chamomile Roman
Organic Geranium Bourbon
Organic Spike Lavender
Organic Lavender Fine
Organic Lemon Balm
Organic St Johns Wort
Organic Rosemary Verbenone
Organic Clary Sage
Organic Thyme Thymol