Yea, this stuff is terrible. Grows TOO well. If only my nuclear green palythoas would grow like that! Oh, and my acroporas!
HATES the stuff. So I am stuck with pulling it out and flushing it!
I dont cut with scissors because:
1-The stuff releases a NASTY substance that I believe nuked my tank last year.
2-It will rapidly grow back and continue to encroach.
You may try putting a torch coral near it.
Its not that hard to just grab the stalk with tweezers and carefully pull the hole critter off the rocks. Run carbon while you do this as the stuff fouls the water when bothered.
Ive got the giant kind that DOESNT pulse. So in other words, an eyesore that bothers the other corals. I was able to pull most out though.
EDIT: Maybe Jimbo could lend you his mean acan to "teach it a lesson".