I have never been able to get ghost shrimp to breed, which is unfortunate because I like the little buggers.
Why are you trying to get rid of them? They should do a pretty good job of helping the tank. I don't think they eat algae like some shrimp species do, but they do graze on live plants and clean up the biofilm that lives on them. They also like to clean the glass. You could always give some of them away or set up a new tank with fish that like to eat the youngsters. You'll probably have to feed the shrimp specific food to make sure that they are a healthy option for any new fish, but that's not hard to do. Puffer fish will usually eat shrimp.