Peppermints are great if you can find some that will eat aiptasia, and you dont' have anything in your tank that eats them. Otherwise kalkwasser paste has been the most effective and the safest treatment I have used. Boiling water is pretty ineffective and its almost impossible to treat more than one plus it stresses the aiptasia causing them to spread. Lemon juice wasn't even 50% effective. Joes Juice, Aiptasia X, Blue Life Aiptasia control are all pretty much the same. They all are variations of a kalkwasser paste, you can make your own out of Mrs Wages pickling lime which can be found in the grocery store in the canning section with the mason jars. To make it mix 1 part lime to 2 parts boiling saltwater and stir it well until there are no lumps then pour it into container to store it and use it after it has cooled. This recipie is very effective and the least expensive method and I have used it to kill several thousand aiptasia.
To treat the aiptasia you will need a syringe, then turn off all of your pumps and powerheads and wait for the water to still. Now you use the syringe to apply the paste to the mouth of the aiptasia and it will ingest it, don't touch the aiptasia with the syringe and try not to disturb it too much otherwise it will retract and expell all of the solution. Once you treat all of the aiptasia leave your pumps off for 20 more minutes and then turn them back on.
Kalkwasser can spike your PH so starting out I would not use more than 5ml in one treatment as long as your tank is 55g or larger, less if it is smaller. Keep an eye on your PH and if it spikes too much reduce the amount that you use in one treatment or you can use more if there isn't much effect on your PH.