Just look at the slime on the retaining wall and driveway at this house in Bli Bli. A stone retaining wall is a beautiful feature for any home, but when it grows black with slime it just looks messy and unkempt. Using the Jetts pressure wand, we cleaned all the slime and grime off the rocks, leaving the retaining wall looking great again. The driveway was also black with slime, and not only looked terrible, but was also a safety hazard as it was slippery. Using the Jetts surface cleaner and pure water we cleaned the slime off the driveway, leaving it looking good and much safer to use.