I juice to make weight for jiu jitsu when I'm being lazy.

10 days MAX unless you consult with your doctor.
Do 85% veggies, 15% fruits (more veggies the better)
Try to get dark greens
When you get hungry, snack on nuts and whole wheat bread or bran

Cheat snack would be beans (for me at least)

Damn; Someone beat me to it.

And here is something to read while you are sitting there.
https://www.miamiherald.com/2009/02/1...-my-colon.html
(The product is mentioned in the article).

"And then, when you figure you must be totally empty, you have to drink another liter of MoviPrep, at which point, as far as I can tell, your bowels travel into the future and start eliminating food that you have not even eaten yet."

OOF, fish juice Fridays are going to suck. . .

You need protein and fruit or vegi juices hardly have any. After about a day without, the damaged or worn out proteins in your body just stop getting replaced. From then on you lose muscle mass, including from the heart.

Also, fruit juices are high in sugar. A woman at work likes a maple syrup fast. I didn't bother questioning that one, but it isn't much different from a fruit juice fast.