Rewrite a repo removing any traces of personal email address such as commit email, email, and sign-off.
git-filter-branch is slow. Also, it is known to be problematic. I have experienced the slow but didn't run into the problematic part. Instead, I just went for using git-filter-repo.
git-filter-repo was not straight forward to get installed on Windows. I tried several ways to get it working that I won't explain here. What worked was installing Anaconda and then pip installing git-filter-branch.
In an Anaconda prompt, I typed