I don't want to start another chain lube war here, but try a wax based lube for the chain now that you have the pulleys clean. You won't ever see that kind of buildup again. The downside to wax is that you need to apply it more frequently, but the upside is the chain doesn't get nearly as dirty. I can run my chain through my hands with minimal marks, and then what does get on my hands washes right off.