Look, highlighting the slave labor isn't the angle to go here... because most stuff you have is made with child labor. Unless you are rocking New Balance, because they are made in the US, you can't really say much.
Just go with the angle that they are using CK to jack up the extrinsic price of the shoes ----> so that poor urban kids pay about 1000% the intrinsic value of the product ----> urban youths cannot afford said product -----> urban youths kill each other for said product. ----> this move will just end up leading to the deaths of more urban youths than cops ever will. ----> yea, CK really cares about Urban youths. ----> end argument.
That way you take any foreign/hypocritical element out of the argument.