I think taking a more discreet approach is ideal in this situation. Keep encouraging her to be open sexually, buy her slutty outfits, encourage her to wear them and be friendly (make sure you back off her though) should she start flirting with other men. R'n'b clubs are great to meet black men. If she can dance sexually, all the better, tell her you can't dance. Go get some drinks or something, if you take your time, it won't be long before she be grinding crotch to crotch with a sexy black man.
Another way to tempt her is to have a black acquaintance seduce her. Once again, back off from her and give her lots of space so she can get to know the guy. Especially with a hot guy, it won't be long before she's unable to give in to him.
Good luck!