When you are a young woman just getting your period, it's confusing and messy. Society doesn't help in that it's also taboo. There is a lot of fear and worry involved with having your period that lasts for many women through their lives. I have friends who won't use a tampon that doesn't include the applicator [1] (it helps insertion without needing to get your hands dirty). So using a cup means, you are 100% going to get blood on your hands and you are going to be very intimate with the inside of your body. For many women who were brought up conservatively, and for those who remain conservative, this will never be an option. I try and promote the cup among my friends and encourage young girls to experiment in safety. Long-term, it will become more popular.

There is also the issue of needing clean running water or wet wipes. Hygiene is crucial in cleaning the cup between changes and of course, you need to be able to clean your hands and have running water to deposit the menstrual liquid [2]. I'm not sure how this would work with a non-flushing / compost toilet actually, I found this article [3] which concludes that of course, blood is good for compost. I don't know what the sanitary conditions are in the kind of home these girls live in, in Kenya.

[1] http://becomingagirl.weebly.com/applicator-tampons.html

[2] https://store.lunette.com/blogs/news/how-to-clean-menstrual-...

[3] http://minimotives.com/2016/11/10/periods-composting-toilet/