Real life Slick 50 / PTFE additive experience. I have rebuilt / repaired countless engines over 40 years and have a good sense of engine wear / what is still OK to run.

Circa 1992 customer ( electrical engineer at a nuke engineering company ) had a early 60's Ford truck with a 292 Y block. He had owned the truck since the early 90's and did proper maintenance all along. As a test he had used Slick 50 at some point in the past.

One day he lost oil pressure and chose to drive it 4 or so miles to my shop. The oil pump had picked up a hard piece of something causing it to lock up and twist off the oil pump shaft.

With the engine in the truck, I pulled the rod bearing caps off and found bearing wear to be consistent with the trucks mileage with the forward bearings more worn then the rear.

Pulling the main caps and found the rear bearings to be slightly more worn than mileage would suggest. As I worked forward, the mains where progressively more worn and 2 had transferred babbett bearing material from the lower shell to the upper shell. Not much material was stuck to the crank.

Cleaned the crank, rolled in a set of rod and main bearings, replaced the oil pump and drive and the truck was just fine,

The Slick 50 did help the engine run without oil however, I don't think it would do much in a properly operating street engine other than reducing start up wear when oil pressure it low. The treatment might help a race engine that sees aerated oil / intermittent loss of oil pressure but the real fix there would be a dry sump oiling system.

If I was faced with loss of oil pressure with a cam in block engine, I'd overfill the engine by 3 qt or so to get some splash oiling. An overhead cam engine would need some sort of upper oiling so blocking the breather might draw some oil to the cam / rockers or pull the valve cover and manually dump oil on the cam.