Aptasia-x is what I'm currently using to battle the little suckers. You use a syringe and inject a liquid, that when it hits the saltwater turns to a glue-like substance, into the mouth of the aptasia. Works immediately, is safe for the rest of your tank, and is borderline fun to do lol. As far as the shrimp, according to my lfs (who is actually quite knowledgeable and not just trying to sell stuff) and what I've found, the peppermint shrimp is imported from the atlantic or pacific and its the atlantic peppermint shrimp that eats them. Though some are still better than others at the job.