You starting from the lowest settings and you get up until there are no more overlapped points .
Just move the slider from lower to upper settings slowly
It will detect the overlapped points and clean them , not much more to it and a simple task. Just practice with it and learn as you go based on your results on the screen.
Overlapped points do not remove frames, it only remove single points that don’t belongs to the main scan that are closest to it , not confusing with lose points function, as lose points remove parts from the main scan if it is not attached to the main scan .
Both of the functions are very helpful but not guarantee complete clean in all situations, it depends if the scan quality .
In cases where the cleaning is much harder to archive you can use Cloud Compare .
You can check this tutorial for Cloud Compare to expand your editing skills .
And please if you have issues cleaning points or are not as advanced , use the Advances mode for fusion to avoid issues to the limits .
That what the mode was made for , it will not produce less detailed scan results