It is sometimes useful to get rid of all the cruft you’ve built up locally
without manually going in and deleting files individually. Here’s how to get
that done with built-in git
functions.
To list what will be deleted without actually deleting it:
$ git clean -n
To delete all your local untracked files:
$ git clean -f
To delete all untracked files & directories:
$ git clean -fd
This Stack Overflow answer was useful and provides a bit more context.