Remember safety is always important when working with a pressure washer.  Some times there are chemicals involved in cleaning some stains.  Thus, we always use some type of eye protection.  Also, when you are using chemicals you need to wear safety clothes to protect your legs.  Chemicals made for concrete are very strong and should not be toyed with.  We may use rubber waders or some type of rubber boot.  They will keep feet from getting wet and keep them from getting burned by the 250 degree water.