I had an old 68 GMC pickup and tried it for shits and giggles, seemed to help with oil consumption but that was about it. I noticed coming out of the can it looked like very fine metalic flakes mixed in, so that is why I was thinking it would be picked up in the filter before it did any good.
Thought maybe YB could do a Myth Buster on it.
In 1996, I bought a 460 ford for 100 bucks.
I put a bottle of that Restore in.
I put over 1500 passes on that engine over the years in 2 different cars.
I took it out in 2009 and removed the oil pan. I was amazed I did not see any residue of that stuff at the bottom of the pan.
Can't say for sure if it works or not because I only put that one can in. I was just happy that my oil pan was clean.