You're doing nothing wrong, you are analysing the files to be deleted. To delete the files to be deleted, press the Run Cleaner button on the lower right. There will be a warning that you are about to delete files forever, click yes to this.
You don't have to run the analyse step first if you don't want to, CC will still go ahead and delete what it should.
I did that exact thing.....and it shows everything that was deleted successfully, but when I look back into analyze, it shows the list of things scheduled to be deleted....even says that they are not deleted yet.....what's up with that?
it looks as though the items have been deleted....but why does the analyze show not deleted? This worries me.....
Run Cleaner - get the warning message, say yes, get the same list of stuff now saying has been deleted
Run Analyse - says zero bytes to be deleted
That's if you have your browser, especially FireFox, closed, but as there will be an error message to this effect this should be obvious.
There will be some files that are listed in Analyse that aren't actually deleted, such as index.dat files, as these are deleted at the next pc reboot time, but these won't show in the second Analyse if you haven't closed/opened CC in the meantime. Also a long list of cookies will remain if you don't close Firefox.