I did a 6-day waterfast and seems like it did not do any difference. Well, our body has taken years to accumulate toxins, it wont take overnight to cleanse out. I read in a book that it takes 3 months for our blood and 11 months for our cells to renew. The author told of a client who had b.o. and was healed after a year of weekly 24-36 hrs water fast. He also went thru one 7 day and one 10 day water fast.
Another author said that there's no benefit from 24 hr fasts as our body would still feed from stored fats within 24 hrs from start of fasting and this is the general theory.