nautilus .thumbnails directory wasting space with old thumbnails

If you look at your ~/.thumbnails directory in gnome, you might find out that there are tens or even hundreds of megabytes wasted to thumbnails of files that aren't on your system (thumbnails of files that have been moved or renamed, were on removable devices, ...). Since I'm always running out of diskspace, I'd like to "fix" that. There are several "easy" solutions: delete the whole contents of the directories in .thumbnails. But then the "good" thumbnails are gone too, and they all need to be rebuild while you're browsing your filesystem.
A better solution is this python program I stumbled upon: thumbnail-checker.py and the .glade file for the gui: thumbnail-checker.glade.

This program reads the original filename from the EXIF info, and checks whether a file still exists The disadvantage of this tool is that thumbnails of commonly used removeable device, that are not attached during the run of the program, are also removed. I'll try to adapt the script so that in te future certain paths can be excluded.