Hi, If the info is available on that site I don't know about it. I got it from a forum on HSIBaltimore.
No, do not peel the eggplant.. I'm told the juice will be a brownish color and some posted that they keep it for a week and then make fresh. Depending on the amount of tonic used, it would seem to me that smaller batches could be made. In fact I recall one posting where the lady used less than a gallon and got great results and surmised that maybe by using less water her tonic was more concentrated. One could also eat cooked eggplant and monitor the bp. but for continuous use, the tonic would seem easier. Omie