First time I ever saw anyone use brake fluid on tires was in the Army back in 1970. First Sergeant made us wipe all of the company vehicles tires down with brake fluid to make them shiny before a big inspection. Personally, I prefer the clean, black, low gloss look rather than shiny.
Years ago I did learn one thing to never put Armor All on - your motorcycle saddle. Took a few rides before I didn't have to hang on for dear life everytime I took off on my bike. Never did that again!