For many years, after making full image backups of my OS and Data partitions, I have used both Auslogics and Wise registry cleaners mostly with success. Now, I don't know where courage crosses over into foolhardiness, however, I have used Resplendence Registrar Registry Manager to mass-delete -- won some, lost some. Before using RRM, ensure you have made restorable full images of your OS and Data partitions on external media.