I only use products designed for fly line. Fly line costs $50 - $100. I won't risk that to save a few bucks on line treatment. I'm still using SA Ultra Line on one of my rods and Cortland 444 on another.
My problem is how do you know Armor All is non hurting the fly line? It is not like you put the stuff on and the fly line is destroyed the next day. Any damage is probable cumulative and leads to a shorter life with cracking eventually. If the line would have lasted 7 years but lasts 5 with Armor All, you would think Armor All did no damage because the damage occurs over years.
I use Scientific Anglers Line Treatment and Zip Cast.
Regards,
Silver
"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy