You mentioned - not being a virgin to fasting. Don't know if you have done this one before.
I will guess not, only because the SWF (Salt-Water-Flush) experience sounds a little new.
Anyway, one of the nice things about the Master-Cleanse is that it cleanses out the reason for craving certain things. For instance - caffeine.
If you were to get all of the residues from earlier cups of coffee completely out of your system then theoretically you wouldn't crave coffee.
Cigarette smokers have great success doing this cleanse and throwing away the butts.
A cigarette smoker doesn't crave a cigarette till after the first one. Then there is enough cigarette residue in the system to cause the craving.