If I were in the automobile product business, I would take my cue from the pharmaceutical industry. The drug companies buy televison time and make commercials where a bunch of symptoms are listed and then one is supposed to ask his/her doctor if a particular medication would be right for that condition. There are gullible people that, after seeing the commercial, have those symptoms and want their doctors to prescribe that drug. Well, I would describe a lot of automotive symptoms and these gullible people would believe that their cars had these problems and ask their mechanics if this treatment would be right for their cars. These people would imagine that their cars had these problems. I would then give mechanics a kick-back to use this snake oil product.
As others have said, you don’t need a fuel system cleaning. Modern gasolines have detergents that normally do this job.