Cleaning Copper heatsinks?

I've got a Zalman passive heatsink that's managed to acquire a good amount of 'roasted' dust and Copper(I) Oxide (the orange/black stuff); adding to that, there's the shape of the fins making cleaning difficult. What suggested ways are there to clean it?

image: http://zip.4chan.org/g/res/81544.html

run it under water and dry completely. should remove the crap from within the fins