No, the down side is them not surviving in the tank, ie
getting killed.
Print out the brand name, and item number and take it to
your lfs. If they don't have the breeder net they should
be able to order it for your, and get it in within about a
week.
The nudibranches 1 to 3 will gang up, and destroy one
aiptasia about every other night, and in the morning after
lay a batch of eggs.