Lets look at a list of instances (with heroic difficulty) where a lock can use some of it's skills, or where CC is not really a huge factor
Let's start off with instances with several demon/elemental mobs.
Mech, Bot, Underbog, and MGT all fall into this category. Technically SV does also, but most people will skip the elementals and the only one you need to worry about are the ones at the first boss.
Now let's look at instances that don't require a lot of CC.
Black Morass, Arc, Blood Furnace (except for that event), and Ramparts all fall into this category. You can put Crypts here also, but those non elite adds can be quite a pain.
Now let's look at the remaining instances.
Slave Pens, Shatterd Halls, Sethk halls, Shadow Lab, Durnhold, and Mana Tombs.
Honestly Slave Pens is really easy and most random groups should be able to do it. The other instances are pretty CC heavy. I'll be honest though when I say that no one likes doing SethK halls, SL, Durnhold, or Mana Tombs. Most people consider them to be too long for the badges.
So in the end, you should easily get groups for instances that people want to do, but you might have more trouble getting into the ones people don't generally do.