It would be great to get the herbs, L-Ornithine, L-Arginine and Iodine but I live in Japan and they are not readily available...
Importing from America sometimes ends in having stuff confiscated as the laws here don't allow for importation of mildly strong substances by individuals. Asking for them even in a drug store is difficult because, a) they rarely have what I want and, b) they ask questions like 'what will you use it for'. I asked for food grade Hydrogen peroxide and made the excuse that I would use it for sterilizing cooking utensils (because they would never approve of brushing your teeth with it) and they flatly said 'NO'.
But, since my first posting I do not have headaches at all and the tiredness has nearly gone, I can work no problem. So I think that being persistant and being careful not to zap for too long when feeling tired was the key. First time zappers should go easy if they don't want to feel too bad.
I am using Dr Clark's original version of zapper (B-5) so I assume it is 30kHz as it states in the instructions.