I have a lot of background which I am not about to lay out.
Suffice to say I don't agree. I understand the reasoning for cooling the laptop. BUT IF it has ruptured, it WILL ignite. I don't know what the FAA has tested but I do see them inact procedures with superficial data then when enough people get killed they examine it harder.
If you truly question the lethal application of water try it yourself. Worn out lap tops are cheap enough and your tech department probably has a couple to test. Testing was my whole premise. I don't see any testing; just a lot of guesses.
I don't presume to know the best solution but it would not be hard to try several things with real test. I really don't see why some main stream flight departments are not doing so.