It would be convenient if TC let me right-click "encrypt file(s)" like I can right click "compress files".
* Create a mini-container with exactly the right length
* Encrypt a copy of the desired files
* Secure overwrite of the original files (DOD 3 pass by default, user could select in preferences one pass of zeros, DOD 3 passes of randomness, or NSA 7 passes of randomness).
Mounting the "mini containers" as a drives might be a bit awkward if the user opens lots and lots of them. That's a design challenge that TC's UX designer would need to tackle.