I thought I would give New Londo Ruins a try because I had a few transient curses, I'm level 50 now, and I finally have some good gear (stone armor). The problem is, even with the curse activated, certain ghosts are still impervious to my spear for a pretty good chunk of time. Also, a group of like 10 ghosts that I couldn't hit because they were clipped in a wall destroyed me and I lost about 10k souls. I'm down to one transient curse now and I don't know where else to find them aside from the vendor, which is apparently a limited supply.

Anyone have any tips for Londo Ruins? Farming transient curses? I didn't want to go for outside help but all of the ghosts hitting me through walls and the impervious ghosts are driving me up a fucking wall. It just feels glitchy and unfair so that's how I'm justifying this to myself. so there.

From what I understand with ghost is best to have a weapon with holy ( or divine or whatever) on it .

I went there with a lvl 15-20 character couse I was stuck on Capra Demon a few hours ago.
The only real problematic thing with ghosts is their phasing through walls/floors.
 
You need to be mindful that the transient curse is always on you. It creates a sparkly effect around you. You probably couldn' hi the ghosts for either of 2 reasons: curse ran out OR their hitbox was in the floor too low/high for you.
The game seems also pretty smart in dropping transient curses. When I use my last one it will frequently drop more on the next ghosts.
I used the Drake tail sword and that thing kills them in 2 hits. Large weapons will also stagger them. 

 Also found a ghost blade somewhere deeper in that area. This weapon basically always hits them without the curse even, but it's not that great in dmg.
 Divine weapons are also supposed to work by themselves, but I have not tried those out.