SSH X11 forwarding with sudo and missing magic cookies

So you’ve fired up your X11 Server, connected to something remotely, sudo su -‘ed to root and gotten the following error:

MIT-MAGIC-COOKIE-1 data did not matchTraceback

There are a ton of posts floating around where you run xauth list in your pre-root account and then copy/paste them into xauth add commands after sudoing to root, or any one of a number of ugly-looking one-liners, but do you know what’s much easier?

[sammitch@jerkstore ~] sudo su -
[root@jerkstore ~] xauth merge ~sammitch/.Xauthority

Done. It seems simple, but for some reason I’ve never seen this posted as an answer to any discussion threads about this error.

The caveat to this being that it might clobber the pre-existing entries for other users running as root, but who cares about them, right?