Is it legal for an underage CNA student to wash genitals of people over the age of 18?

I apologize for the rather embarrassing question, but I have a concern for my school's CNA program. I am 17 years old and am training to be a Nursing assistant.
One of the "skills" we are taught is Perineal Care and it is the cleaning of the genital/perineal area. We are instructed how to do this on a mannequin and that is how we test.
But, in order to receive our license we must have hours in a real facility. It has come to my attention that I am expected to perform Perineal Care on adult patients, but I don't think that is legal.
Is this legal? And if it isn't and I refuse to perform the care, can I have my license revoked?