Looks like a redbug irritation, especially since all the polyps are closed. I saw this white bleached pattern in a coral I recently got, but only after I blasted it with a MJ1200. Seems to have blown off the necrosing tissue, causing the white patch, which didn't show before the blasting.
Also looks like irritation from an acro crab, but don't they usually stick to a general area, making ID easy? The location of the problem in the pics suggests to me something is nesting there.
As to interceptor, I used it a year ago with success, but is the coral able to be removed from it's perch and blasted with a PH in seclusion? May save some trouble killing innocent byswimmers.
I'm still waiting to see how my blasting goes, after a week no bugs and it opened it's polyps that night and started colouring-up the next day, to my happy surprise.
HTH
TimO