Well, that's a new one on me - I've used water stones and oil stones, but never heard of a wee wee stone!
I've seen similarly priced and looking stone on ebay. Although the price is tempting, as someone getting into honing I just don't feel comfortable learning a new skill on an unknown tool... That being said I did luck out with the "Imperia la Roccia" 12k stone I got off @HolyRollah. The WeiWei stones could be a good deal, but for me I'd rather go with a proven stone then price.
For the few times I've used it, GREAT! I've been busier than I'd like the last month or so and have not spent much time honing.