Waterbased polish?

I might be repetitive, but I am thinking about nailpolish. Waterbased or even watersoluble nailpolish. Polish that can be considered suitable for children.
I read wixology's post on the subject a while back and since then, I've been looking for it more than ever. Searching for reviews, brands and retailers. Asked around, but it didn't sem to be anything sold up here (in Scandinavia). Waterbased nailpolish, it didn't even seem to be on the map with our local manufacturers!
I emailed a few companies, including Piggy paint, and none had retailers here in Scandinavia. I could always buy it online, but with postage and customs fees, that could end up being a rather expensive affair.

But if these polishes are as good as the manufacturers say, why aren't they taking over the market? Why is nobody talking about them other than the occasional beauty-mag mentioning Sula as a cool green alternative?
Are they that bad? Is the formula off or are we expecting too much?  Or is it that the colors are more, well, suitable for children?