Look for a bottle that says "complete fuel system cleaner" or similar rather than just "fuel injector cleaner." The active material is often the same, whether it's Techron or something else, but you get a higher dose in the "complete fuel system cleaner."
Detergent performance can be simplified by how far downstream the hardware is. A little bit of detergent will clean carburetors, more detergent will clean intake ports, even more will clean valves, and the higest amount will often also clean combustion chambers and piston tops.
Aftermarket treatments that sound passive (i.e. the product "cleans" rather than "cleans up" or "removes" deposits are often just a maintenance dose; something that adds only a little detergent and for adequate cleanliness, should be used every tank. The economics for these products are ... good for the marketer.
Some of this stuff gets in the oil. If you use aftermarket products, try to plan to use it a tank or two before an oil change.