All the parlour girls use sponges as they normally have fixed day or days at each place and don't want to keep changing their day one week in four. I had a WG as a girl friend a few years ago ( no I am not a pimp- most girls are quite capable of looking after themselves ) and did not know about sponges until we became friends. I have even bought sponges for her from Boots! They cut a small piece off and pour boiling water on it to steralise it. As a punter you will have no idea that it is there and there is no odour or trace of blood as long as they change it regularly.