I have only been to one Lady who beside the mouthwash provides disposible cups.
I would like to think that although a Lady could have many faults with me (middle aged, fat and unattractive) hygiene would not be one of them.
So when asked to shower and use mouthwash I have no problem except for the fact I will not use the bottle that X amount of guys have used.
To avoid conflict I always bring a breath freshner in my pocket.
But please Ladies, for the guys that make an effort.. buy the cups