Got session? [SOLVED-ish]

[Silent Warrior]

I'm at a loss for where to post this, so I'm dumping it here:

I've got 17 sessions in my session menu in KDM/GDM, and I would like to trim it a bit. Having poked around with Arch a few times, I'm confident I can do the dirty work on my own, if I only knew what file(s) to clean up/spatter with #s. I swear I only need one guest-restricted... Well, if even that, since I'm the only one using this laptop.
I think the big source of the clutter is really my attempts at trying out Gnome 3 + gnome-shell (no need to rant, this was for curiosity's sake) - I spot Gnome, Metacity, Gnome 3, Unity 2D, Ubuntu 2D, Gnome (no desktop effects)... A list with less than 10 entries is a clear win in my eyes.

Yes. 17 "different" desktops (at least two give me Gnome 3 + Shell, and two drop me in Unity - I used to have another 2-3 because of the E17 PPA, but...). Help a man out, I only have so much vertical space...

[Update]
Rrrrrrrright. Well, after ploughing through Arch's Wiki, I found out about this little directory: /usr/share/xsessions (not for the faint of heart, I guess). Anyway, I've found what I'm looking for. Now to see that it gets duly trimmed.