@neil

Based on the later half of your post I assumed a simple way once you've booted was of use.

Don't know of any truely automated ones other than the ones you've already mentioned. Looks like there is a succesor to DBAN.

If might be able to slip stream a simple script to run on boot of a live bootable USB stick, especially if you know which device it will be.

I would add if it was very sensitive data and an SSD, I'd stick it through a shredder.