Yes, well rotted cow dung is fine on clay soil - the myth about its not being as good as horse was because it was believed that cow dung, being wetter, would make the soil heavier. In reality, it doesn't.

I recently read it's less full of weed seeds than horse, as it's gone through 4 stomachs, but has a smidge less nutrient value.

Ok thanks l will give it a try.