I used white vinegar and a needle syringe. Took me about an hour, and I haven't had any problems since. I just couldn't see spending $10 on Joe's Juice when I already had vinegar in the kitchen cabinet.
I have been fortunate not to have many. The few I have had I have removed by taking the rock they are on out of the water. Then put the rock in a bucket of tank water. Make sure the aiptasia are at the top of the rock as you place it in the bucket. Adjust the water level so the the rock is submerged as high as it can be while keeping the aip out of the water. Then dump salt (that you would put in your tank) on top of the aiptasia. Let them sit there for about 10 minutes. This is a guaranteed way to kill them with no side affects since you are just using salt. You wouldn't need to put the rock in tank water while you do it, if you don't think you have anything on the rock that would die off that quickly.
And the super glue did not do anything to the other fish in your tank??
I probably will not do it that way. I am going to see if my peppermint shrimp will do the job for me.
Superglue is completely safe for aquarium use. In some ways it is ideal because it cures when it is exposed to moisture, not when exposed to air, so it will cure underwater. It is most commonly used to attach coral frags to rocks.
When it comes time that you need to use it, do a search on this website for superglueing and you'll find plenty of info on how to do it. Superglue gel works best.