i have mentioned previously that my SO was overseas doing NGO aid work in 3rd world countries for some years. Her take on the straw (and other similar products) is that although the straw probably does work as advertised, the downside is that these types of methods are slow and singular especially when you consider how much potable water a person needs per day. Also the fear of human cross contamination is a big factor as these straws are probably not stored nor sanitized and probably used by more then one person despite precautions. My SO also mentioned the cost of the straws. Even if they were $7-$10 per, there are not many aid agencies that could afford to equip hundreds or thousands of people with these straws as other mass water purification methods are much cheaper and more efficient on a large scale.

My take on the straws for what we would use them for is the real lack of advance use. Meaning that although you can safely drink through the straw as needed. it does you no good if you need to travel with water stored in bottles. Whereas other treatment methods allow you to treat water as needed and also that treated water then can be stored in bottles and taken with you and used where there may be no other replenishable water.