Purge extension
This extension is currently being distributed along with Mercurial.
Overview
This extension purges all files an directories not being tracked by Mercurial in the current repository.
It'll remove unknown and ignored files, as well as empty directories.
It keeps added files and (unmodified or modified) tracked files.
Configuration
Just add a new entry in the extensions section of the mercurial configuration file (hgrc):
[extensions] hgext.purge= #or, if purge.py not in the hgext dir: #purge=/path/to/churn.py
Usage
To purge the repository contents:
hg purge
To list the files that would be removed by running the previous command use it with the --print option:
hg purge --print