Turin - I do not have access to a 757 QRH, but assuming it is SIMILAR to the 737,
When in caution zone, wheel fuse plugs may melt. Delay takeoff and inspect after one hour.
When in fuse plug melt zone, clear runway immediately. Unless required, do not set parking brake. Do not approach gear or attempt to taxi for one hour. Tire, wheel and brake replacement may be required
Of course you are correct in what the OP says, I am merely raising a metaphorical quizzical eyebrow due to the lack of information (hence my earlier question) since I would think it reasonable to assume they were in the 'caution' zone since 6 wheels blew? How would you have handled that?
The problem with water as I understand it is that the shock to the wheels can cause dramatic failure of the wheel assembly which with high pressure tyres can cause significant shrapnel as bits explode. I'm sure I saw a safety film once where bits went everywhere at very high speed. I'm sure a fireman will correct me.