I have not used ThreadSearch much, but the GUI doesn't seem to have an option to remove old searches.
The info is stored in the 'default.conf' file which is really an XML file.
'default.conf' is found in
Windows: %APPDATA%\CodeBlocks
Linux: ~/.config/codeblocks
The tag SEARCHPATTERNS under ThreadSearch contains the old search patterns. So it is possible to remove it manually using a text editor if you understand how to not mess up XML syntax.
- Exit C::B before doing anything
- Backup 'default.conf'' in case you mess it up
- Make the changes
- Restart C::B
