[header] How to use a rubbing compound [title] Fill a bucket with water and 2-5 tablespoons (30-74 ml) of soap. [step] To wash your car, it is helpful to prepare a soapy mixture. Washing your car removes any loose dirt, dust, or mud. 
You should always use car washing soap or conditioner so you do not damage your paint. Squeeze a bit of soap into a bucket, and use a hose to fill it with water.