I have tried the male trick and it does work. I have had three different females at different times around 1 KG that stopped eating for over two months I put them in with a male for a week then moved them back to their own tubs and they started to eat aggressively again. I did not see any locks with any of them while they were with the male and none of them have become gravid but they are eating again every week. But I'm sure it is possible for them to breed and become gravid which would not be the best thing for them so I guess its a try it at your own risk type thing but it did work well for me so far.