I tried it once, I made it six days! It was a lot harder than I thought, not necessarily struggling with cravings and stuff (though I might not have made it long enough to really get the strong cravings). My issue was finding stuff to eat!! The biggest thing for me was trying to avoid sugars in non-sweet things, such as pasta sauces and salad dressings, etc... During the six days I did it, I ended up eating a ton of nuts (definitely more than I should be eating due to cals and high omega-6s!!), just because I had run out of other things to eat. If I were to start again, I would need to be way more prepared and have home-made versions of 'convenience' items already made and ready to go (like pre-make my own pasta sauces and salad dressings, etc... without sugar so they would be ready to go to whip up a meal).
The great thing, though, was after the six days, I was down to my lowest weight ever and definitely felt the belly-bloat disappearing.