> The fact you'll be avoiding high-pressure water almost guarantees
> you'll stay out of trouble.
>
> Do not apply WD-40 to any rubber or plastic
> keep silicone oil from getting sucked into the engine

Wouldn't bearings also likely be damaged from a detergent solution?
For example, alternator bearings, electric fan bearings (if any), etc.

Also, what about mechanical fuel pumps (if equipped)?
They may have an air inlet hole, often on the upper half, which might
allow potentially damaging wash fluids to drip onto the pliable
diaphragm.