I haven't ... Very mixed reviews, but lots very good. Perhaps if you get from somewhere that would give you a no quibble refund like Amazon worth a go! Notice they do different scents etc too ... http://www.amazon.co.uk/Ecoegg-720-wash ... roduct_top
Never seen these ones, but we did have EcoBalls for a while, we used them just on clothes, not nappies. They were fine, but it was hard to tell if stuff was really getting clean as none of it goes in particularly dirty... different story now we have kids of course, maybe we should try them again! We also tried soapnuts, which were ok as well.