Can see that she didn't read the instructions as you're supposed to immerse the filter end in the water for around 10-20 seconds before sucking on it, and in that video clip with the amount of cow dung that went in it, well it only natural that it will clog up the filter and make it that much harder to suck water through it. If i came across a river that was as polluted as thick as that one there's no way I'd be in fishing it any way, though if I was in a predicament where that was the only way of getting fluid into the body i would use the life straw in it.