Believe it or not, a tank I maintain was starting to get out of control with Aptasia, and I had no way of being able to kill them manually, due to limited access. I tried a half dozen peppermint shrimp and they wiped out about 30 anemones in 3 days. They even ate some giant ones.
I'm with everyone else that I believe you should manually kill them and not gamble, but if you can't reach them, it's worth a shot.
Just make sure you are actually buying Peppermint Shrimp and not Camelback Shrimp. They look somewhat similar and the latter is a predator of corals.