I wouldn't use the Joe's Juice here, I'm almost certain the Xenia would die. I injected some Apatasia last night, they were all around some zoo's and a unidentified sps. I tried the Joe's Juice about a month ago and it just killed my zoo's and sps(now recovering), the Apatasia seemed to multiply. Didn't have much luck with Kalk solution either when I tried that(I think that is what the Juice is anyways). My stuff is fine today with no signs of damage, I did a bunch of injecting too, about 8 of them, some pretty big. If you don't want to do the boiling water thing, you could try and get the Xenia to move to another rock, and then get rid of the little pest. If you inject it though, make sure to suck out the remains afterwards. I hope this helps a little
Matt