Yup, good old cheap peroxide from the drugstore works wonders. It fizzes and feels weird but doesn't hurt. You can buy stronger solutions made just for ears, also peroxide, but I'd start with the cheap stuff. Warm it slightly to just below body temperature and it is less shocking when you pour it in.

Then flush with a stream from one of those ear irrigation bulbs as said above.

You will probably be amazed at what comes out, even if you clean your ears regularly with q-tips. It's gross. You will hear so much better afterwards, and have a feeling of "opening up" your sinuses, etc.