Shake off all the tangible dirt lightly and use your fingers to unlock curls and tangles. Apart from thorns and twigs and all vegetable matter, sheep wool contains an oily substance called Lanolin which can be removed only with hot water.
Fill a tub with hot water. Bath tubs are usually easier to drain but any other normal one will do well. Pour detergent into it to make it soapy. You can also use the dish wash detergent as it combats 'grease well.' Lanolin counts as grease here. Mix the detergent and water well.
Take at maximum 5 pounds of wool. It depend on the size of your tub, amount of water and detergent. Tie the wool in a gauze and make a bundle out of it. Lower this bundle down into the hot water. Press the wool lightly to fit in. Cover the tub with a lid so that the temperature is maintained for a while.
Let the wool soak for around twenty minutes. Do not let the water cool down because the Lanolin congeals back at around 110 F. If it does, the whole purpose of your wash will be lost. Pick up the bundle of wool and place it in an empty bucket. The water in the tub will now be dirty with Lanolin, wool dirt and all sort of matter. Drain this water. Fill the tub again with clean hot water and detergent. Put the bundle into it again. Repeat the process again until the water in the bottom of the tub remains clean after lifting the bundle. When this happens, put the bundle in a tub of clean water and let it rinse to clear off the detergent. DO NOT touch the wool or press it. Hold the bundle by the knot.
Once the bundle is rinsed, take it out to an absorbent surface like sweater racks and spread out the wool. Be light on the touch and try to place it in an airy location. A wire mesh may prove as the best place for drying because it lets the air circulate. Some people are innovative enough to make a gauze basket for their fabrics.