I think fuel injector cleaner is something similar to "snake oil".
And I have seen some manufacturers actually state to not put any cleaners inside the fuel tank as it can eat at seals or loosen up solidified dirt chunks or what have you in the tank. That is coming, not word for word, from my shitubishi FSM for my 2010 Lancer.
mind you that is what a fuel filter is for to catch the sediment.
In my opinion the best fuel injector cleaner is one that can be used with mixing with the oil. Like marvel mystery oil.
I always use this stuff for rebuilding engines because it eats at carbon build up and really does take it away with ease. I think to chase bolts with it too and it works for that too.
Now Marvel Mystery oil is a true snake oil but it works for the oil and cleaning sludge out and I have put it in the tank before. I do not see any changes because if your injectors are good then how can you clean injectors that are already clean?
If you really wanted to go the extra, pull the injectors, take them to a fuel injector place and have them flow tested and then they will clean them. Its money, like 10-20 an injector depending on if its port or direct injected.
thats my 2 cents probably more than what you wanted to know lol
The best way to keep injectors clean is flooring it lol