I think they are referring to Cosmoline. It's that dull brown/yellow coloring you find on the crankcase. It isn't found on every component in the engine bay.

 

I know what you mean, I get paranoid too whenever I wash my 997.2 with the entire engine wet comes sloshy wet. I solved the problem by cutting a sheet of plastic canopy that I tuck on top of the engine bay and then close the lid This way regardless of how much water I sprayed through the air vents, it will stream away to the side of the engine bat and channel it out. I was extremely happy in avoiding all the vital sensitive parts getting wet. After I'm done wash and drying the car, I just pop open the lid and remove the plastic sheet, leaving the entire air box, filter, alternator, belts, pulleys etc... all bone dry.

 

this

Also, the cel is more likely to have come from your battery compartment getting wet.

 

Mine always squeals after a wash.

one blip of the gas, and it goes away

 

Same here. I usually power wash mine in a bay. I usually go pretty easy on the rear slats area. But every time I do the initial crank after a wash, you here the creaking/groaning from the belts and then it goes away after 2 seconds.

 

Mine squeals too but only noticed after I stopped hand washing it myself and had a co come to my home to wash with a sprayer. When I used to hand wash it was with some blue solution I think it was made by that Opti co. maybe it's called opti clean and it gets heavily diluted with water. One gallon and one tentacle micro fiber sponge and one panel at a time from top down. I'd dry each panel with a micro fiber cloth right after I wiped it down. Worked well and hence the water in the eng or other cracks was always minimal. Maybe I will start doing that again. It's a small car hence doesn't take too much time.