I think he may be implying/referring to the aspect that on some metal tanks, its better to leave them full of treated fuel, as opposed to letting them sit empty, and thus having the ability to rust.
I leave all my equipment with full tanks of treated fuel, metal and plastic, and never have emptied any of my equipment or run it dry ... doing it for all my life .... I do treat all my 5 gallon gas cans with 2oz of Stabil as well as 2oz of SeaFoam.
I do however run all my equipment periodically throughout the year, even in off season. I am a believer that no piece of equipment should sit idle for any great length of time.
Yep, that Seafoam is good stuff. I use it for my mower and snowblower in season, added to the gas. One time I left the fuel in over the summer, the carburetor was gummed up when I went to use it. But, no additive was in the gas either. My mower and snowblower service guy recommended running it empty after the season. I doubt very much that any rust will develop in the Honda tank. I will keep doing what I have done now, for many years.
Officially washed up and put away here in New Brunswick, Canada. Spent an afternoon this weekend cleaning everything up, lubing and coating, draining fuel and making some minor repairs. All ready for fall now. I figure anything from here will just be left to melt.
I have to say it looks like winter is going out with a whimper not a bang.
I have four different blowers to spice up, fix and maintain before I can hide them away.
Don't worry about summer. I will have plenty of questions.