often seen in the street without a hat

A mooncup is a menstrual cup - it's sits in the vagina in about the same place as a tampon, and the menstrual fluid collects in in. It can be emptied as and when needed, simply by taking it out and either wiping with tissue or rinsing, and is not associated with TSS. Between uses, it should be sterilised, either by boiling, or by using sterilising tablets, like you do wtih the nipples on babies' bottles.