Gasoline additive for carb messed up from sitting?

I run the gas out of my mowers and small equipment by using a shutoff valve. 1 can of seafoam to about a 1/4 tank of fuel run it up to temperature, shut off fuel and let her run till she dies out. Leave whatever is left in the tank and put premium in next time I go to use it. So far so good, flat slide dirbike carbs are a pita to rebuild sometimes! Be mindful how much seafoam you are putting through a small engine like a chainsaw etc... Small gastanks won't need a whole can maybe a 1/3