Hello Arlen!
I wish you good luck on your 40 days fasting journey. Good for you.
The longest fast I did was 7 days. I started with 3 days and then 5 days. Now I am looking in to going to 10 days and beyond.
To prepare my body before going to my last (7 days) fasting I did Liver-Flush and a day juicing, that really helped me getting rid off the headache and sluggish feeling of the first three days of fasting detox.
I used to do SWF (Salt-Water-Flush) and enema. But I found that Liver-Flush is more superior.
Today I am going to do the Liver-Flush and then proceed to the Water Fast after a day juicing.