I have used Oxypowder and it does seem to work. I really don't know if it is worth the high price that they charge for it. The main benefit of using Oxypowder over Epsom Salts or other bowel stimulators is that they use ozonated magnesium oxide. Ozone is an oxidant which helps to destroy bacteria and other undesired materials in the bowels. The question I have is how much ozone does this product actually contain and is the ozone still active by the time it is encapsulated, etc.? There is really no way for us to know.
Overall, I would say it is a decent product, but I probably would not purchase it again as it is a bit pricey and there are many other products that you can use that are just as effective.