Quite a bit stays inside the torque converter. If you use a pump to flush in new oil (many shops have), that should force old oil out of the converter. I think the oil gets hot enough to slowly evaporate any water. But, the paper clutch plates are quickly ruined by water, so that is only good to get any remaining residual water out. Perhaps if you heat the milky oil on a large camp stove, you can boil the water off and make it usable. Given ~$40 cost, might be worth the trouble.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans