So to sum it up: i would like to help, but i have no idea how to clean my data or prevent more wrong entries in the future.
Don't worry about it. With v1.8 those entries will be cleaned automatically and they will disappear from your database when synchronizing. Don't try to erase them manually.
Even if zone names are the same, I can blacklist entries by category name or quest name. It can and will be done in v1.8.