It doesn't make sense that stopping short of "finishing" would negate the benefits of the fast. Over the 21 days of fasting, you eliminated a lot more than just 21 days of accumulated toxicity. So assuming you do not wait too long between fasts, with each fast you should be getting cleaner. And even if you do go a long time between fasts, you're still going to be a lot cleaner the day after you break your fast than the day before you started it. Again, the body is not stupid. It is not "all or nothing." It doesn't go through the trouble of the cleansing process only to revert back to Square One because your caveman ancestors finally found a gazelle to kill and eat.