Self-cleaning glass does work, but it is not a 100% maintenance-free product. It requires UV light and rain (or water) to work, so areas where there is the most exposure will show the best results. During dry spells, a rinse with a hosepipe will assist with this rinsing action. For real-life case studies and to see it in action visit our specialist website www.selfcleaningglass.com to view our 'Success Stories' video.