Its the small metal pipe that goes from the carb to the cylinder head

Getting ready to put the snow blower into summer storage. Its a Honda snowblower and the owners manual basically states to either drain the tank and carb or leave the tank full of gas with stabilizer. I do have a full tank right now, with Sea Foam (liquid) added for stabilizer, but am not sure what would be the best method. I have a can of Sea Foam Deep Creep spray that I could use also but am unsure the proper method of spraying into the air intake so as to allow it to penetrate into the carb. Before the last season summer storage, I recall I had a helper who sprayed the Sea Foam into the intake, I believe while the engine was running, until big puffs of black smoke appeared briefly and then shut it down. I tried myself yesterday, I removed the air cleaner and shot a few sprays of the Sea Foam while the engine was running but got seemed to get no different response from the engine and no black smoke, so I think I wasn't doing it quite right or something. What I'm trying to inquire about here is what's a good method to store the snowblower, using the Sea Foam, so that I can be pretty sure there won't be a gummed up carb or other such fuel problem caused by old fuel sitting in it all year until I need the blower next winter? Just draining the gas out of the tank and carb seems like thats not going to be thorough enough. Any comments/advice appreciated.