I had one 5 years ago. Doing without alcohol for 4 days was an interesting experiment, and I am happy to say that I did not experience any craving. Despite my faithfully following the instructions (living on Sprite & bouillon and all that jazz), I was told that the doctor could not see much. The nurse warned me that the sedative would cause amnesia, but evidently she did not warn the doctor, so (I was later told) he told me a number of things I did not remember.