they are correct, you do not need to use any flushing product or conditioner if your engine does not require any such repair. Infact keep in mind that while a Honda civic is considered luxury and super duper limousine level coach in Pakistan it still is a cheaply built econo car around the world. It was never specced for any expensive engine oils either.
Use oils with the best cost/run benefit. Anything more is a waste of money.