i very much support the idea of voluntary sterilisation WITH compensation.
at the moment undesirables are the highest output in breeding terms. where white families that care about their progeny will only reproduce if (if!) and when they can afford to support them well through schooling and into a good position (btw, this is how jews and indians still do it), the undesirables spawn with impunity at every opportunity, without regard or intention of support, causing the offspring to grow into a further cycle of poverty and crime.
the natural greed of these uncouth monkeys would easily allow them to trade chemical castration for the price of their next hit of crack, some watermelon, and maybe a bucket of kfc. to my mind this is a small price to pay.