I havnt faced any problem I dont know what kind of phobia people have with regards to engine bay washes. Washing an engine bay is safe as long as you know what youre doing.
I am getting my 7th gen civic washed with pressure washes + degreaser + surf excel + what not as I like to keep the engine bays sparkling clean and I havnt faced a single problem Alhamdolilla. I have been doing this since last 10 years on the same car.
I am yet to see a method where you can clean an engine bay upto the mark with a duster.