I’ve updated my collection of Mac OS X command line tools with improvements to the
trashcan now list trash contents across all volumes (with a disk usage total) as well as empty the trash (including a secure empty option; both emptying operations require confirmation).
Note: Obviously, the new version of
trash is now destructive. I have tested and use this myself, but I cannot guarantee it won’t securely erase your entire hard drive if it encounters some odd edge case and I cannot be held responsible for that. So, use at your own risk and keep backups!