I remember when you could buy a "water injection system" waaaaaay back when cars had carbureted engines. Really just delivered water througha vacuum port on the intake manifold. Buddy of mine had a Winnebago with over 100,000 mile on it when he installed it. Thing slowly ran worse and worse over hundreds of mile until it just would run with enough power to barely propel the beast down the highway. Took it to a nearby RV dealer/service center. When the wrench saw the water system he explained that those vehiles had carbon build up problems and that he'd clogged his muffler with 10 years of carbon build up, replace the muffler and all was good. Being a young guy at the time I just held the throttle open on a 427 of mine that had a sticky float for some time and trickled several gallons of water down the carb. It may have run a bit better or not. But, I have never repeated that stunt.
Before I hit the "Post Reply" button I thought I ought to Google this water injection thing because nobody's going to believe that anybody would do that. Turns out, lots of people did it years ago and, apparently for good reason. I am including one link below that is both semi-educational and slightly entertaining. (But doing what I did is apparently not done by anyone with 1/2 a brain although my wife tells me that I would be qualified in doing it.........)
www.stovebolt.com