They appear to work, but more often than not it's a 'don't believe your lying eyes!'
First things first. I helped start this craze years ago at Reef Central. Go check it out. The first post about using a laser on aiptasia was started by me. I got the idea from a local friend who using one so I bought one, and then a stronger one!
If you use one, you have to destroy the entire aiptasia, right down to the last tiny bit of it's foot. Many are in holes that you can't get the straight line laser beam all the way into the hole. You lose and the aiptasia wins as it comes back a week later! Many, many will grow back in a few days to a week. Yes, if they are on the surface of something you can kill them. But in my experience the percentage of REAL success is about 30 to 40%.
Don't waste your money on a laser or a majano-wand. They kind of work, but they are FAR, far from being a serious solution. Sorry I ever got so excited when I was first using a laser!