If you buy little mini barbless (fly fishing shop, like size 10s) hooks and using fish line, you can attach a piece of raw shrimp to it and wait for the pregnant shrimp to take the hook. VERY SLOWLY (as to not hook the shrimp), bring it to the surface and grab it with a net. Last time my cleaner shrimp was pregnant, I was on a stool from 9 pm till 11 am. SO get prepared for a long night if you want to get it out. The only cool thing is that they seem to be the most aggressive when it comes to lights out feeding.
Also, I don't even know if you have any rock in your tank. But most fish arent going to mess with your hand in the tank let alone a hook after lights out. But thats why you use a small barbless hook. If you hook a fish, just hope it falls right off.
Coral Frenzy is a better food because of the Micron range. That stuff gets SMALL! But there is no reason why a quarantine tank shouldn't work as long as the parameters are the same. If they aren't, the shells will become extremely soft and fall apart.