Worse.
We just had a batch of rock brought to us from someone exiting the hobby. The boys have been on a murderous rampage with the stuff for 3 weeks now. Aiptasia X works well, but it's not a one-shot deal. There are always ones hiding that we miss... so it takes a little while to get them all.
Not much eats them - a few butterflies do but those species will also eat your coral.
Curiously, the other day Scott dipped a rock in straight vinegar (the rock had no other corals etc., on it) and the Majanos died instantly (acid - makes sense)... of course goodness knows what other good micro flora and fauna were sacrificed too...
I recommend Aiptasia X - we've tried other preparations: Joe's Juice, Stop Aiptasia, home-made kalkwasser paste, lemon juice... and others, and so far the Aiptasia X has done the best job.
Jenn