Is "Gummout" a good product worth purchasing?

Just a W.A.G. here, but thinking he meant more of the application process, as in long trip, going to be hammer down all day long as opposed to 5 miles today 3 tomorrow etc.
I personally don't use additives anymore and believe they can cause more harm than good. I did recently use a bottle of Berryman's to clean the fuel line (metal portion) of a 1968 Corvette that has been sitting since early to mid 80'. That stuff did a great job keeping it corked up in the line for awhile.

 

Excellent YouTube channel, wasted many hours there!

 

My mom & dad use this crap. I don’t & my mom has kinda back off since buy a new ram 1500