If you eat you are no longer fasting. At this point is is just very low calories and high carbs diet. To me it would sound like a pain to deal with.
Worst part of a fast is the time when body switches from burning sugar to burning fat. By typing yourself of you with soup and juices you pretty much guarantee yourself that this switching happens for you every couple of hours and that your insulin is always maxed out to deal with the carbs you are introducing.
If see no upside to this and planty of downside to such diet.
There is a lot of misinformation on fasting and heck, dieting in general. Take breakfast, “the most important meal of the day”, a concept created by the post cereal company and repeated by most doctors and researchers without real evidence to support it; most studies have been observational where you can’t tell if the people are better off because they eat breakfast or because those inclined to eat breakfast are more likely to do other healthy things.
Skip the advisories and the articles, look for studies that have done the lab work. Fasting works best once you reach ketosis which won’t happen if you short circuit the process.
I know Buchinger Wilhelmi Clinic uses this method of therapeutic fasting with 200 calories a day coming from consommé broth or fruit juice. Up to 35g of carbs from the juice. I have a hard time calling that “fasting” and I’ve had a hard time finding the science and benefit behind it. The clinic claims their patients benefit from autophagy, but I’m not sure how. I know for myself, if I had 200 calories of juice there’s no way I could fast. I’d be starving. The only way I can fast for long is because my insulin is low.