Doing winter setup for highway plow gear (graders, loaders) they would receive a VERY liberal coat of fluid film on all internal areas that were reachable. Under hatches and covers particularly. Electrical cables and connectors and all. We'd use it from the bulk gallon containers and shoot it with a shutz gun. The exterior panels wern't covered with FF. When the equipment was returned in spring a thorough hot water pressure clean was standard. This removed most of the FF coating. Worked well and kept rust to a minimum. This was for gear that was on salted roads 24/7. Would I do it for my BX on my driveway at home? Probably not. Not that its expensive (the treatment is under $100/gal) but there is only minimal salt on my drive and my tractor never sees the highway. If I had a larger machine that was used for plowing as a business? Absolutely, FF is cheap insurance.
Rust check is a great product. But the red can is intended to be sprayed into cavities like when undercoating a car. Its a thin, penetrating, creeping oil (great for hinges and locks BTW). RC has a newer product that is called Coat and Protect that comes in a green can. Its thick and stays where its sprayed (minimum creep). Its a close equivalent to FF. IMHO it would be a better product for a tractor. Its neater and stays put.
One last product is called Krown. Its what I use on my personal vehicles. Its thick like FF too. Almost like really soft butter. It works extremely well. You can get it from just about any Mack/Volvo truck centre under a Mack PN and save a bunch over the Krown dealers prices.
This is the product in a 20L bucket. Enough to do a couple cars and still some left over for the tractor/ PN# M20LLR