The longer story is that it probably won't work, because your Mac probably doesn't have the same X11 fonts installed as does the remote server. The older hint actually addresses this, but the explanation is confusing, and it only works if there is no firewall between you and the server. The fix is to forward the TPC port of the X font server over the SSH session, so that your local machine can actually talk to it. Here is what the entire setup looks like:
localhost% ssh -L7100:localhost:7100 -Y user@remotehost
(in another Terminal window)
localhost% xset +fp tcp/localhost:7100
(back in the first window, after it has ssh'd into the remote host)
remotehost% Xnest ":1" -geometry 1280x810 -query localhost
Discussion:
You have to have the ssh session open, with the port forwarding active, before you will be able to add the remote font server to your local font path. And you have to have the remote server's fonts in your font path before it will be possible for the remote desktop session (CDE on Solaris in my case) to start up.
One of the problems I had with the old hint was that it said to do xset +fp tcp/ip.of.remote.host:7100 and I thought he meant "use the tcp/ip address...", when actually the prefix tcp/ is really part of the syntax. The other problem is that it wasn't clear where you were supposed to run the xset command, or for that matter why you'd be tunneling X in SSH at all if there wasn't a firewall in the way.

