I did "use" them. That's how I found out you can't. I also have discovered that a huge percentage of the population, not limited to non-photographers, can't recognize when something is in focus. Out of focus is not commercially acceptable, which is how I mostly have "used" my cameras.
However, if you enjoy buying equipment, accumulating stuff you can't "use", then buying Russian lenses is a good way to feed that beast. Personally, I don't feel right leading people down that road, but you obviously don't have a problem doing that.