Not only grapefruit, but pink grapefruit specifically and when Dr. Clark was alive we asked her and she had her reasons.....and suggested a liver flush every 30 days for life and at double the book suggested dosage...double epsoms salts, double the oil, etc.
I have NEVER liked grapefruit as they were always shipped in and bitter. Fresh off the tree ripe as can be, they can taste great.
EVERY TREE / VINE juice will work for fasting,for a liver flush, you want to pucker up that liver, so the pink grapefruit is best...but the epsoms salts is the mirical drug......100 years ago it was seen as the MIRICAL DRUG and I 100% believe it is and luckily in the USA it is not classified as a drug, you can buy it by the ton, matter a fact, I just purchased 500 pounds yesterday to put on the hay field and black berries....