First, fucking minorities does not absolve someone of racism. Racism is a much deeper issue than mere physical attraction. White slave owners fucked their black slave women, yet that didn't change the their enslavement or that slave master's opinion of black people.  

 
With that said, I am not accusing you of being a racist. Rather, just pointing out remarks that appear to be thinly veiled racists accusations, and what appears to me to be hypocrisy.  

 
I do understand your position, though, and I am not discounting your experiences. It would be foolish to claim blindness to cultural differences. If I were in your shoes, rather than discriminate against a race or nationality, I would strongly make the  rules known in every appointment confirmation and follow-up before the actual appointment with a big disclaimer that any breach of these terms will result in immediate cancellation of the appointment without refund. Maybe even make them acknowledge and accept the terms  prior to meeting. I'm of the opinion that you have to teach people how to treat you.  Easier said than done, I know, I am just saying that in my own life I opt for an approach that guarantees that anyone who is going to be in my company is going to respect my boundaries. This way I am filtering out people solely on character and the respect they show me.