Is this Uncle Ian's castor based?
I have used the stuff you get at Lowes, and farm and ranch stores that is basically corn cobs ground up and mixed with castor oil. My moles and pocket gophers just ignore it. In this part of Oklahoma I have found nothing that even seems to slow them down. If you kill the grubs they eat earth worms if you kill the earth worms they must live on air, I don't know. The gophers help themselves to my garden produce eating cabbages and tomato plants and beans. I have actually watched a tomato plant about a foot tall slowly sink into the ground as a gopher pulled the whole thing under ground as I watched. When it was done there was not a leaf left on top of the ground and only a hole the size of the stem of the plant. It was fasinating to watch. I have tried a lot of different products and nothing seems to bother them. According to Oklahoma State University moles usually have a population of only one per acre, and pocket gophers about the same,but it sure seems that they are double bunking on my place.
Mike