Cleaning Indian sandstone is simple. Use soapy water and a stiff brush or hose. For tougher stains as well as moss and algae, we recommend using New Clean 60 available from our website. Apply as directed with a sprayer and leave on for around 60 minutes then wash off with a stiff brush or power washer to ensure you have removed all dirt and debris as well as any cleaner residue. For further reading please follow the link to our tech guide