What better way to avoid a second waterboarding than to tell them simply everythiing you know to a "T."
This is going to end up in the DD, but the argument is that the boardee will say anything regardless of if he actually knows the info or not. How does the interrogator know if the person has spilled all the beans. That is why KSM went through it 183 times.
So, can you actually drown via waterboarding? If so, I wish they would've finished the job on that douche Mancow. "Sheesh, what a worm." (name that movie)
Its probably only useful to extract certain type of information which can be verified, i.e. a password to a locked file.
They might give up confederates and so forth and so on.... "did something" is past tense. There may be other things planned.