A little late yet thought I'd stick my head in here...
Depending on the ailment, sometimes acidic foods are surprisingly
a relieve for digestive problems, especially over acidity.
I agree that testing the waters/lemonade is a great idea.
I would suggest skipping the swf and tea initially.
If in fact the McCocktail is more than tolerable,
maybe then go on to the prescribed plan.
It is however tough to really give advise blind. More research
on the part of your friend would be wiser than me tossing out
blind ideas. The Master-Cleanse is good yet everything has it's application.