The tool is often found within the payload of the SaRA installation.
Understanding SetupProdOffScrub.exe: The Ultimate Microsoft Office Removal Tool
While you can sometimes find the standalone .exe on GitHub or tech forums, the safest and "top" recommended way to get it is through the official Microsoft channels.
Common errors when an old installation is blocking a new one.
It is a Microsoft-vetted tool, making it safer than third-party "registry cleaners" that can often damage your OS. How to Get and Use the Tool