the basic 15 covers all basic nutrients we need, if we are allergic or reacting to these, our health would be affected and we would be reacting to more foods because they are the core nutrients or components in foods.
for example, vitamine A mix, if one is reacting to it, then you will react to carrots, multivitamine pill, etc. then treating carrots or the pill individually wont solve the problem entirely and it will take you much longer to get rid of one allergy/intolerance, iykwim.
How old is Katerina? It would be beneficial to keep a food journal for all foods and drinks and reactions. She might have tested a whole load of things as it goes very quickly.
the handbook explains what you have to do before, during amd after the treatment and what to avoid during the 25 h avoidance period. you can order it from amazon.co.uk.
How did you find your practitioners? There have been reports about practitioners not following the code of practice.