about the cleaner's speed of browsers

For example in firefox, the speed clearing internet-cache by using borwser's build-in tool is more faster than CCleaner does.

CCleaner takes almost ten times slower to complete it, so CCleaner often spends over one minutes just clearing firefox internet-cache.

Is it possible to improve speed? tkank you!

the operation would be interesting (deleting 1 file after another or deleting the whole foldercontents in one... or so)

You can increase the speed by unticking/disabling:

Compact Databases

I unticked it ages ago because CCleaner takes too long with it enabled.

Thank you , Andavari.

You are right , when i tick "Compact Databases" that will been take much time to finish.