Due to GDPR regulations (or in other cases) it is sometimes a requirement to remove files from OneDrive permanently. This includes removal in recycle bin and second-level recycle bin as well.

Currently there is virtually NO way to do this for a large number or files in a complex folder structure due to the following limitations:

1.) Deleting the files themselves
1.a) Webclient doesn't allow to delete folders without removing the contents first - an painstaking work with complex folder structures
1.b) OneDriveSync goes completely fubar when one tries to delete a structure of several 100.000 files in a few 1000 folders
2.) Removing the files from RecycleBin
2.a) Webclient removes only a few hundred files when one uses the "Empty bin"-function. So there's no feasible way to to this with several 100.000 files.
2.b) Powershell-Function (Clear-PnPRecycleBinItem) is also limited to a low 1000-files amout - so even when scripting, it takes DAYS to remove the mentioned amout of files.
3.) Emptying SecondLevel RecycleBin
3.a) see 2.a)
3.b) see 2.b)