I seem to recall the exact same thing with the "Slick50" fad back in the late 80s...
My dad insisted that I use it on the Orange Peel. (That was the nickname for my bright orange 1973 Datsun 240Z that I drove back and forth to college.)
When I bought it in 1984, it was over ten years old, not in the greatest shape, and I only paid $1100 for it. Had 86,000 miles on it, the clutch slipped, the gas gauge didn't work, it had low compression and it burned oil, hence the $1100 price tag. My dad thought I was crazy to spend that much money on a used car. By early 1986, I had done a full top end, replaced the rings, carb, clutch plate, transmission, fixed the gauges, replaced the wheel bearings, and just about everything else mechanically. I even replaced both door windows and their mechanisms. I even got something called "Re-Nu" which was a paint oxidation remover. It went from dull hazy to bright - you could read a newspaper in the reflection - orange. Orbital polisher and everything. When I finally sold the Orange Peel in 1992 a couple years after I married, it had over 155,000 miles on it. I wish I still had that car. And I don't ascribe anything to the Slick50. I just used good Castrol oil, checked it frequently, and changed it on schedule.
Ahh, those were the days.