What I did that worked years ago is to connect rubber tubing from the washer reservoiur motor to the carburetor opening and attach above the throttle plates. Fill the reservoiur with water and run the car on the highway.
Every few seconds hit the windshield washer button to spray water down the carb. This works because you are decarbonizing the piston tops when the engine is under load full temperature..
Sounds feasible: guessing you'd want some sort of smaller small hose/spray type nozzle at the carb end. Don't want to inject a "gulp" of water each shot.
I actually used the same windshield washer resorvoir hose from the washer pump to the carburetor. No spray nozzle was used. It worked well.
If you want to put a spray nozzle at the end of the hose; maybe go to Lowes or Home Depot and buy a misting nozzle that's used for outdoor sprinkler systems to water shrubs.
The misting nozzle line attachment is about the same diameter as the washer hose.
