Fill a cleaning bucket with hot water. While you are filling up the bucket with water, add three squirts of liquid dish detergent to the water.
Dip a clean sponge into the soapy solution. Scrub the plastic furniture with the sponge.
Rinse the sponge with water from a garden hose, once the sponge becomes dirty. Continue washing the furniture with the soapy solution.
Inspect the plastic furniture for remaining stains. If some dirt stains still remain, scrub the stains with a clean rag dampened with white distilled vinegar.
Spray the plastic furniture with water from the garden hose to rinse off remaining dirt, soap and vinegar. Dry off the furniture with a clean towel.