the idiotic service stations in US are self operated, hence you cannot blame the station, but there in Pakistan the stations are operated by nincompoops...
bear in mind I also lived there for most part of my life and had a car business there, Im not speaking hypothetically or anything, For clarification I would like you to please tell us your lovely service station experience in Pakistan..
I'll put mine first, You never ever ever wash a normal temperature engine - the thermal difference can literally warp metal out of shape of even sieze/damage items inside it (diesel injection pumps specially)..
Secondly - you never wash under the car with mineral oils etc. It eats out the wax coating applied by the manufacturer. You are supposed to use neutral non sudsing detergent and hose off with a pressure wand.
Never ever should the paintwork be washed with laundry detergent mixed with Kerosene or diesel fuel.. It destroys the paint top coat.
Did I not envelope all the service station practice above?