Cockroaches are tough, as all of you who have to put up with them know.
IF you do not have children or pets that walk around the house freely, you can mix borax and sugar and put it into all the dark spots, which is where cockroaches like to hide. But even this it might not be enough and you will need professional help.
If anyone has good ideas, ideally tried and tested, of how to get rid of cockroaches naturally, please comment !