Well folks, I tried writing the plugin code, but it took me for ever to work out the basics, and it still had a ways to go... and I just don't have the time. I still look forward to working with others on this, but by myself, who knows? Months, at best.
Meanwhile, I'll try to upload an updated standalone (but large...) version at www.ebookcleaner.com
. I also updated the source code here (a huge amount of changes and improvements, and I restarted the numbering from version 1.0.0) for anyone interested in working with it to create a calibre plugin; but its back to py3.2 for now.
@atjnjk: yes, it is based upon his project, but much improved.