Interesting that it got the GSP also. Maybe it'll work for folks who want to not have GSP any more, though that might be less common than blue cloves going nuts, since GSP doesn't spawn in aquaria.
Useful information, thanks.
This is exactly why I came here to read all this. I'm going to try breaking off the section of rock they are attached to first but ordering the meds to make a dip as a backup. I scraped and peeled and sliced with a razor until the mat was mush and they STILL came back. Now they are irritating an acro and have got to go.