See-through Bullet Holes

I am trying to create actual bullet holes in my walls. I am not “destroying” them, I just want to see straight through where I’ve shot. I’m not sure where to start on this one…

I know how to do decals, but I suppose the best option is editing the texture at run-time?

Wait! I’ve possibly found the post …

http://forum.unity3d.com/threads/35808-Projecting-a-hole?p=232985