@kevo_koma:
When Luffy was thrown into the lake in arlong park, Nojiko was still able to stretch his neck so that he could breath. So Brook would still be alive and Chopper would still have human traits but they wouldn't be able to do anything until they slowly drowned to death.
Which actually raises an interesting question. Why isn't CC using his abilities weakened as they are, especially the suffocating trick to make a break for it. Plus he's been pretty spry, especially if we consider that Luffy always seemed to nearly pass out whenever he came into contact with the things. Oda perhaps forgeting?
Luffy doesn't lose control of his ability, he simply becomes extremely weakened to the point where he can't move a muscle. I'm assuming the same thing happens to every other Devil fruit user, except apparently CC.
So when Brook or Chopper fall into the ocean or whatever, they'll simply become weak and pass out. The sea will not take away their ability and therefore Brook will still be alive and Chopper will still be human just passed out and soon to be dead
When is said that the water makes a devil user loose his power, what it really means is that he looses is physical strengths, is unable to intentionally use(trigger) his devil fruit power and swim, not that the devil fruit powers disappears. Don't forget that Luffy's Paramecia, rubber effect is permanent and not triggered by him.
Luffy would still be rubber, Brook would still be alive(it was already seen in Sabaody Duval mini arc, when he drowned), Chopper would still be in his current transformation. But neither Luffy would be able to stretch HIMSELF, nor Brook able to use the underworld ice, nor Chopper able to use the Brain Point Scope technique. If Buggy body is similar to Luffy, He doesn't need to trigger anything to split it in parts, then when he fall into water he wouldn't be able to separate into parts, but if somebody cuts him under water he will still divide into connecting parts as always.
Handcuffed with Kairouseki a devil user, like in water, will loose is strengths and be unable of trigger any kind of power. Normally a Logia user needs to trigger is element and CC isn't a exception. He can't turn into gas and he can't use any of his attacks based in gas.
Luffy only looses strength when he touches Kairouseki, not becomes close to pass out. His reaction is because he is Luffy and because he still tries to use force even when he don't have any(or have little).
Becoming extremely weakened to the point where somebody can't move a muscle is pretty much losing control of ones abilities, but that is not even true in this case! Luffy moves a lot when touching Kairouseki. Luffy, Smoker, Ace, Buggy, Alvida, CC and others that I don't remember right now, were still able to move when in touch with kairouseki. CC is not a exception, but the norm.