Well in a car engine the antifreeze never touches the bearings, piston or crank. Even in the water pump the bearings are isolated from antifreeze. In fact it is a seal leak into the bearings that washes out the grease they run in that causes the failure of the waterpump. Traditional green antifreeze deposits, over time, silicates on the inside surfaces of the cooling system. You can see them when you disassemble a car engine and the inside of the cooling system has a distinct color.

Now I am totally unsure of the amount of silicates that would accumulate in just a few hours or days immersion. It must not be much if any because a lot of model engines seem to have received this cleaning and must function well or their owners would be screaming.