I want to back up the contents of my Macbook before encrypting it, but after I'm done, I would like to sanitize the SSD that I have backed up my files to, since it will be unencrypted (no point encrypting your laptop if someone can just steal your backup drive and get your files from there). I think I read on Apple's website that OS X's
diskutil secureerase command is not available for SSDs. Or was that just
diskutil secureerase freespace that's not available for SSDs? I don't know. I can't seem to find the page. I don't see why secure erasure of an entire volume wouldn't be available for SSDs though. What are some good options that I can use? I don't feel any need to use Gutmann, since that's only necessary for HDDs. A one-pass random bit secure erase should be sufficient.
EDIT: I would delete all files on the SSD before doing the disk sanitation of course, so all blocks would be available for reprogramming.