While this isn't a Yorkie specific product, I just bought the Bissell SpotBot and wonder why I didn't get it sooner!! It works great for carpet stains, old and new. You put put the machine over the spot, turn it on and it does the rest!!!!
I bought mine at Amazon.com and was able to order pet stain remover as well. I would highly recommend it.
http://www.amazon.com/gp/product/B00...SIN=B000ASDCXY