i believe in using regular seafoam in a spray bottle into the carbs, the running good doses in the fuel. and keep using the seafoam. it also work as a great starter fluid on hard to start engines.
A little 3 gallon tank is definitely the way to go; you can control the ratio effectively. Allowing it to soak for awhile is pertinent to an effective cleaning. Sea Foam is the product most everyone on this forum uses. It will smoke, not a little, it will smoke a LOT!!!
If you want to be nice to the neighbors you might try 1 pt to 10 gallons of fuel and run it all out at one outing over the period of a couple of hours or so out on the water while having a little fun.
Then keep it in the gas. I use Sea Foam available at Autozone and NAPA to name a couple. I usually pour some in when I add gas; like 4 oz per 5 gal or thereabouts.
If you are really gungied up then you might have to use the 3 gallon approach like in the pic.
