
Tomato juice stained our mostly white ESS pale pink. Perhaps if we'd washed and washed her repeatedly with shampoo after the tomato juice we could have removed the pink but the poor dog had been scrubbed with, I think about 20 tins of tomato juice and rinsed, for so long we figured she'd had enough. Another bath a week later removed most of the stain.
It's funny you have such a problem with fox poo. We have foxes too but I have never heard anyone complain about their dog rolling in it. But, as fox mating season, late Feb. and early March, is near and the air will be ripe with the odour of "vixen fixin' for some mixin'" (complements OH) which is faintly like skunk mixed with lemon, I wonder if your fox poo does actually smell like a fainter version of our skunks?
For skunk and other odour we really like Canadian Odor Control Deodorizing Shampoo. I buy it locally but I think you can order, even in the U.K. It's easy on the skin and gives a beautiful shiny coat, at least on the two dogs I've used it on, so we just use it all the time. And it works way better than tomato juice.
P.S. Admin, hope it is OK to say the product name. Please edit if not.