If I had to ditch a twin jet like this 777, or the similar type that I fly for a living, I'd take the advice in the QRH and do it with gear up and full flap.
I guess that if I made a decent job, the damage would be limited to the flaps and the rest of the aircraft would be left floating intact.
Then, the crew and I could evacuate the aircraft and hope for the best.
But if pax already asleep, then crack the doors open and wait for it to sink.....no more debris would be released.