If you are using Android 6 or above, CCleaner does not have rights to access parts of your internal cache. This means that CCleaner cannot fully clean certain files from your device during cleaning. To enable CCleaner to perform a full Clean, follow these steps:
- Once analysis is finished Tap Show results.
- Ensure Hidden Cache is ticked.
- Tap Finish cleaning, then tap Enable in the dialog that appears.
- Scroll to the Services section and tap CCleaner.
- Tap the slider next to
OFF so that it changes to 
ON. - Tap Back to return to CCleaner where the enhanced cleaning automatically starts.