I've been with two girls with pierced clits. One said it enhanced her clitoral sensations during sex, the other said it made no difference. I've also been with a girl who had her prepuce pierced and she said it made no difference. However, I prefer for a girl to have nothing pierced down there as it keeps me from doing the best I can when I give her oral. I've never heard of a guy's sensation being enhanced by a woman's piercings and in my experience that didn't happen.