I wash mine in the sink too. I use Dawn Simply Clean dish soap (diluted one part soap to 2 parts water). Gets them squeaky clean in no time. (Jan Griffiths).
The Peter Stone foal with the pumpkin marking also has a cat on the left side. At least the big one looks like a cat. Kind of like Breyer's Salem, which is an awesome model. I have him. (Jan Griffiths).