Warrick Shannon and Dustin Scott are part of a global street art movement crafting beauty from dirt. The Durban artists use the "reverse graffiti" technique to create urban artworks in their city's streets, a technique that involves placing stencils on filthy walls and cleaning away some of the dirt using steel brushes or high-pressure hoses to form a design."We basically use elbow grease," said Scott. They first create their stencil out of durable plastic before placing it on the wall."We then literally just take a steel brush and brush away the dirt to reveal the clean concrete. We never use chemicals." Work can take hours.The artists like to involve community members or anyone interested in helping to create their artworks."Internationally, reverse graffiti's been a thing for a while. There was a guy in England who came up with the idea of creating graffiti by cleaning walls. There are other artists in Durban who have been doing it for longer. We picked it up last year and did some pieces in Durban, Umhlanga and Ballito."Scott says the idea was to clean up walls that were grimy and add something interesting to them. "We like to leave spaces looking cooler and having an art aspect to them."The team asks for permission to work on walls whenever possible. They favour places with "concrete walls in high-traffic areas", such as bridges."We've had a mostly positive reaction to our work. There were maybe one or two people who asked 'are you allowed to do that?'".Removing the artwork requires cleaning off the rest of the wall with a high-pressure hose.A work close to Scott's heart is one they created in Umhlanga as a tribute to US actor Robin Williams following his death in August 2014. The artwork featured the animated character voiced by Williams, Genie, from Disney's Aladdin. It incorporated a shrub that was sprouting out of the wall."We thought; let's do the genie pouring his magic onto the tree."..