Hi,
Yes this is a bit of a pain. I find that the easiest way to detect these is by viewing a directory listing, whether that's a bag checksum manifest or something else. I just tested this with a bag manifest, a teracopy manifest and an FTk Imager CSV listing and it worked.
You could open these listings in something like Notepad++, or any text editor that allows you to search with regular expressions. I'm purely giving Windows instructions here as opposed to BitCurator itself.
If you search for [^\x00-\x7F]+ as a regular expression, you might be able to detect those characters.Hopefully this screenshot works:
Best,
Kieran O'Leary
Digital Preservation Manager
National Library of Ireland