Naw...dont work like that. Some guys try seafoam to use that way but i have experimented with it and i dont think it is nearly as good as advertised. Try it though. Might clean it up enough to run better.
You most likely need to tear down your carbs and clean and rebuild them.
Marvel oil IS good though, if you get water in the cylinders or to free up stuck pistons. Might buy you another season or two if cylinders arent too corroded or scarred.