New
#11
Delete all of your bookmarks, and re-import...?
zzz2496
If your ISP gives you ftp storage or you have an ftp account check out Firefox SyncPlaces AddOn. It will sync your bookmarks and passwords. The advantage over just exporting is, you can install a version of Firefox to a different folder with a different profile, and just install the SyncPlaces AddOn. Fill in your login info and sync. You can set it to merge everything on download to avoid duplicates.
For example if you were using another machine entirely you could install Firefox portable, install SyncPlaces, and download all your bookmarks and passwords. When done using the PC just delete the folder Firefox Portable is in.
Why not delete the profile, recreate it. The goal is to reset Firefox, right? Instead of deleting bookmarks one by one, delete the whole profile once again, then recreate it.
zzz2496
If you use Mozbackup to backup Firefox you will never lose anything.
MozBackup - Backup tool for Firefox and Thunderbird