Dog Rocks are a 100% natural, Australian-mined igneous basalt used in your dog's water bowl to prevent ugly yellow urine burn patches on your lawn. They act as a filter, removing excess impurities and nitrates without altering the pH balance of your dog's urine. 
You simply place the rocks directly into your dog's water bowl (or keep them in a water jug used to top up their bowl). One pack lasts for up to 2 months and must be replaced to maintain effectiveness. It generally takes about 3 to 5 weeks for the rocks to start working and for the benefits to show on your lawn.