Highly recommend https://binnybin.com/shop/
Act almost exactly the same as traditional bins. When full (with aprox 20 females our lasted around a year, although we have 3 bins, they have a formula within it so there isn’t any smell etc) you seal the lid and take it to the skip. On their site they explain how it works and the sanitary governance etc
Personally when we had normal bins in the toilet cubicals I wouldn’t let the cadets empty them, sanitary waste isn’t for cadets