I generally do not do long fasts because my doctor does not want me doing them at this time. Master Cleanse is much easier, especially when you need to work, or want to exercise. Water Fasting
is much more intense. It takes about ten days of Master-Cleanse
to get the same degree of cleansing as three days of water only. The choice is really up to the individual.
For the purpose of weight loss I strongly recommend Master Cleanse over water only. Master Cleanse does not cause the intense slow down of the metabolic rate, and while some weight will be regained after the fast, it will not be nearly as much as with water only. Master Cleanse is much better when exercise is done because its high Sugar
content and minerals prevent muscle wasting. Remember that muscles need glucose to function.
I just do whatever seems right at the time. I cannot Water Fast
when its cold and right now its 18 degrees with a windchill of zero. So I am enjoying spiced green tea and hot cocoa and not worrying about fasting, just adding some green juice and carrot juice to keep healthy and hydrated until springtime.
Good luck on your MC. Don't sweat the small stuff, just do your best. You have a lot of fasting experience and should be pretty well in touch with your body, just let it be your guide.