I had to look and see what this was as I had not seen it. Wow, it looks pretty neat! Glad to hear a good review on this product!
Here is a link to their website. Perhaps you can buy the refills there...or I would use my own. I know a lot of YTer's are particular about their shampoos and conditioners...
HydroSurge® RapidBath® Pet Bathing System