I've been using these for two years and we have had GREAT results. We currently have two male Weims and had a female on them too. We watch my friends pup when they are out of town and he has destroyed our grass...now we have them on the rocks so that our yard isn't spotty. Would recommend for sure!!!!! PS...you have to give these time. You won't see any change in the a few days. Be patient. I was giving my pups the grass saver pills and those didn't work at all AND one of the pups got in to them and I had to get his stomach pumped because there are chemicals in them. These rocks...are just rocks with minerals that your dog drinks when he drinks from rivers and streams!