I tested it myself, like `ssh git@rando.github.com` and that didn't work.

That was my interpretation of the original comment. (reading it again, it seems like it was indeed saying what I typed below)

It seems like the reply was saying instead you can do in your .ssh/config file

   Host work.github.com
   HostName github.com
   Host me.github.com
   HostName github.com

(or just leave out the .github.com in the Host part)

So `ssh git@me.github.com` now works...

And then key the github config off of that? But I didn't try that part. So I could be wrong there.