Get a roll of 'mason's twine' at the hardware store -- tie on a 3oz lead sinker (the teardrop shape) and toss over the limbs. Make your line about twice +10ft the height you want to reach. On the opposite end, tie on a snap-swivel and connect this to a larger line (I use 1/2" tubular nylon) again, about twice +10ft as high as the limb. Use the mason's twine to pull the heavier line over the limb. You can pretty well clean the entire limb in just a few shakes (if you time it right - when the hulls are open and dry). Leave the opposite end of your heavy line unencumbered (no knots, etc), so it makes it easy to pull off the limb when finished and not get hung up.
You can (as I have) try putting a heavier sinker (up to 16oz) on the heavy line - but it will wear you out after just a few throws. Also, the lighter sinker/line is really easy to throw (and I've reached near the top of some 70-80' trees) - and, with practice, you'll get quite good at it. A *whole* lot easier than tossing any heavy line system.
-- john.