Per your question, we are not talking about erasing the OS drive(s) that are currently in use.
Keep in mind that the tool required depends upon the drive because different types of drives use different storage technologies: hard disk drive v. SSD v. USB flash v. hybrid. I assume you are referring to standard hard drives.
If the drive itself is compressed or encrypted (e.g., NTFS option), the rules are different. Individual zip files or files compressed or encrypted by 7-Zip, AxCrypt or the like are just data files with weird data but compressed or encrypted disks behave differently (see SDelete discussion referenced below).
If you go the CCleaner route, remember to clear the recycle bin! Also the filenames will not be securely deleted (but data "should" be) and there may be some miscellaneous file fragments left. If the drive itself is compressed or encrypted, I'm not sure that CCleaner will do what you want.
SUGGESTION: Check the vendor website for each of your disks. Some disks can be 100% securely erased in 1 second by overwriting an internal encryption key.
SUGGESTION: Try SDelete from Sysinternals (now part of Microsoft). It is a free program that can be used to wipe drives, wipe files, or wipe free space. The background material is quite informative and will help you evaluate various suggestions. Note that this is not guaranteed to make all old filenames completely unrecoverable but it should come pretty close. File contents will be overwritten.
or search for sysinternals sdelete
The following is adapted from
which also has good background information and suggestions.
Download SDelete.zip from technet.
Unzip (extract) to a folder.
Copy sdelete.exe to c:\windows\system32\ (or the appropriate directory for your OS) so you can run it from anywhere.
Open a command prompt session with Administrator rights (press START button; enter CMD in the start search field; right click on CMD.exe and choose Run as Administrator).
To wipe all files on drive X: and its subdirectories and to wipe free space, enter two lines:
Sdelete -a –s -z X:*.*
BE VERY CAREFUL about the drive letter!!!
Wait: this could take minutes to hours. You'll see status messages unless you use ECHO OFF command.
I used SDelete a few years ago so please report back if you encounter a problem with these instructions or can clarify them.
If you really want to be sure, perform 2 cleaning passes. Anything more than that is not relevant to the technology in multi-GB drives.
Sdelete -a -p 2 –s -c X:*.*
Usage: sdelete [-p passes] [-s] [-q] ...
sdelete [-p passes] [-z|-c] [drive letter] ...
-a Remove Read-Only attribute.
-c Clean free space.
-p Passes Specifies number of overwrite passes (default is 1).
-q Don't print errors (Quiet).
-s or -r Recurse subdirectories.
-z Zero free space (good for virtual disk optimization).