If you are serious, you can have some. Expert grower is a joke, I let them reproduce until they were on the verge of blowing up and taking over the tank to make sure there would be enough to support enough berghia to find them all. Berghia have been in there almost 2 months and I think they have gotten enough to stall the spread, at least that is what it looks like.
I have done this before but it took a year due to a wrasse keeping the berghia population small. Is neat to see, aiptasia multiplies for a while, then stalls for a bit, then you may notice one or two large aiptasia disappear, then one day BAM they are all gone and you have hundreds of berghia searching the rocks for food.