See git gone: cleaning stale local branches.

MIT License

• Store the bash script git-gone where you want (here: C:\users<username>)
• Edit your .bashrc file and add the path to the PATH variable:

  export PATH=$PATH:~/

• Open a Git bash and type the following command to ensure you see the usage instructions:

  $ git gone

• Type the following commands to clean your local branches:

  $ git gone -pn
  $ git gone -d
  $ git gone -D
  $ git branch --merged | grep -v "\*" | grep "wip/\|pr/" | xargs git branch -d