Top Law Schools

If I'm interested in a very specific practice group at a firm, is it appropriate to send one of the partners in charge of that group listed on the firm's website an email expressing such interest and maybe asking a few questions about how to break into that area of law? I ask because my school has a firm policy about not mass mailing firms that will participate at our OCI until after OCI, but I'm iffy on whether this would apply or not.

That being said, is this an approach that ever works, or would it be a waste of my time?

This is a perfectly fine idea. It shows the firm you are proactive about learning more, and the partner might even put in a good word to the recruiter. In no way is it sidestepping OCI so your school would of course be fine with it. As long as you are only looking to learn about his practice and not encouraging him to give you an interview on the side.