How to wash the oil head of a car? Trouble?

There is a shop that specializes in cleaning throttles and injectors. My old car ran 60,000 to 70,000 kilometers, and I thought it was a waste of oil, so I went to clean it, but it was useless. Cleaning the nozzle is to remove the nozzle and clean it with a special instrument for cleaning the nozzle, which is relatively slow. I forget how long it will take. Later, the knowledgeable master said it was best not to clean it, because it would cost more oil if it was not cleaned well. The landlord can buy the kind of cleaning agent added to gasoline, which is convenient and can also achieve the cleaning effect.