Reorient faces coherentely

[wikyburns]

Hello guys, I'm trying to fix this 3D scan by orienting faces coherentely but the filter is doing nothing, any idea to fix that?

STL : https://we.tl/t-TvjH8HiozT

[alemuntoni]

I think that this mesh will require first some other cleanups.
There is a discontinuity between the two portions of surface that have opposite orientations, and you can see this by executing the filter "select border":

Therefore the resulting faces orientation is acceptable given that the two portions are not connected along that border.