TortoiseHg has settings to enable the Mercurial Purge extension. But does it actually have a drop down menu or something so that you can purge a directory without having to go to the command line? Or is that extension setting just a convenient way to editing extension settings without needing to load a text file?
From top menu bar in TortoiseHg Workbench simply select: Repository -> Purge. It will perform purge even without the need to install the Purge extension.