If it is controlled, I'm actually a fan of Xenia. I love the movement it provides. I can definitely understand why a lot of people treat it like a disease though.
I've read this before but I don't buy it. Isn't it something else that causes the Xenia to melt in the first place? I have Pom Pom and Pulsing in my tanks and I've never seen either one melt for no reason.
But if I want to get rid of some off of a rock I clip as close to the base as possible and then scrub the area with a toothbrush.