Remove cushions or pillows from the concrete bench.
Sweep the bench with a broom to remove particles, such as dirt, dust, grass and leaves.
Fill a bucket with warm, soapy water. Use a mild detergent and avoid solvents, such as ammonia.
Pour the warm, soapy water over the concrete bench, but leave a small amount in the bucket. Distribute the water evenly over the bench.
Dip a strong abrasive sponge or a heavy-duty wire brush in the bucket and scrub the concrete bench to lift and remove stains.
Rinse the concrete bench with a water hose.
Dry the bench with a cloth or towel.