Hydrogen Peroxide to bubble organic matter from weep holes seems to be easier than pipe cleaners. Put 1-2 tablespoons of first aid grade hydrogen peroxide into the window troughs. Hear the fizz? Wait 5 minutes. Use a paper towel and q-tip to remove most of the icky stuff in the trough. Slowly pour about 1/2 cup of water into the trough to finish the flush. If you are successful, you will see water coming out of the slits on the outside. Don't pour the water too fast or you will have a wet mattress.
