I definately would not trade them in. Nudibranchs are a pain but they can be dealt with. Dipping them in FW/lugols/FW exit is the so called nudi dip. It will take care of the adult nudi's. You have to remove the egg sacks yourself. If you are just removing the nudi, you are leaving the eggs. I think once they are big enough to see, they can lay eggs.
You will need to remove the rock. Dip it for 5-10 minutes and then put the rock under a strong actinic light. I used a flash light with a blue filter with good results. Take a tooth brush and lightly scrub the eggs off. Then swish the rock in the solution again. The eggs look like a swirly string type substance. The eggs are generally laid on the stalk of the zoo.
I had these little suckers a yr and a half ago. I had to QT all of my zoo colonies and do periodic dips. Some of my colonies did not make it. Some are now making a come back. Some wrasses will also eat the nudi's. I seemed to have good results with a sixline wrasse but the wrasse is hit or miss. Supposedly a sea grass wrasse is the wrasse of choice but they are uncommon and I am not sure they are reef safe.
HTH