Do you have them installed into the default location? If not installed into the default location that will break the cleaning of many applications, although for web browsers CCleaner uses some sort of detection so I don't know if it will fail with them.
Once they're installed they should be listed in the large Cleaner icon, in the Applications tab at the very top. Each browser has their own header/section with the cleaners available for them, such as this Opera example:

Note that the
*Opera (Classic Install) cleaner is not a part of the original CCleaner installation, this is however it if using
winapp2.ini:
CODE
[*Opera (Classic Install)]
; This cleans the Classic Install of Opera where Opera stores all files
; in its program files folder.
LangSecRef=3027
Detect=HKCU\Software\Opera Software
Default=True
FileKey1=%ProgramFiles%\Opera\profile\cache4|*.*
FileKey2=%ProgramFiles%\Opera\profile\cacheop|*.*
FileKey3=%ProgramFiles%\Opera\profile|*.sbsd.bak
FileKey4=%ProgramFiles%\Opera\profile|bittorrent.log
FileKey5=%ProgramFiles%\Opera\profile|cookies4.dat
FileKey6=%ProgramFiles%\Opera\profile|download.dat
FileKey7=%ProgramFiles%\Opera\profile|global.dat
FileKey8=%ProgramFiles%\Opera\profile|Opera.dir
FileKey9=%ProgramFiles%\Opera\profile|vlink4.dat
FileKey10=%ProgramFiles%\Opera\profile\sessions|autosave.win