I was an Evinrude outboard motor dealer for many years and I was asked this question many times and heard it asked at service seminars nearly every session. Their answer was always the same; for those that believe that diluting any fuel system 'cleaner' so much when mixed with fuel does any good, just take a sample of that mix and put a dirty spark plug or something similar in it for a while. You'll find that it is far too diluted to have any impact.

What they always recommended and what I use to this day is the concentrated de-carbonate products. Sea Foam might even be a version of it. GM has them as well as all the outboard manufacturers. JC Whitney had a version that they called 'Tune Up In A Can'. And it really works well in concentrate. But even it will not be effective when diluted with gallons of gas or fuel. It is all I have ever used to clean carburetors. It is very effective, non acidic, water soluble, and won't hurt the aluminum, unlike carb cleaner. There is a lot more to this subject, but that is the gist of it.

This is still what I use to clean carbs and anything with carbon deposits. There are other brands of the same product, too. This stuff has been around for decades.

https://www.amazon.com/Johnson-Evinrude-OMC-Engine-777185/dp/B001KYJAL0