I'm not sure why they have such a high average review. Everyone I know who has the used their products has had the same experience as I have. The oily liquid leaks, not only covering your hands and mouth, but also going into your mouth, which is a deeply unpleasant experience. I found a bout 10 percent of the cartridges I bought (admittedly a small sample, because I stopped using it after about two weeks), were already broken and leaking.