I have tried sea foam with uncertin results, I don't know if it helps or does nothing?
A few people I know claim seafoam is the cause of many carburetor problems on small engines, I don't know about that either?
The one thing I put it in occasionaly will sit for a few years before I start it, and it always starts with only one carburetor cleaning in the past 8 years or so. But the gass always smells bad and I change it before I try and start it.
Bad gas is bad gas, just change it after something sits for a year or two when you eventualy want to start it. and turn it off and run the carb dry when you think it will sit for a long time.