The reef I maintain has a large Red Sea Pulsing Xenia colony that I regularly frag and it grows back faster than I can sell it. I put in an ATS (Algal Turf Scrubber) which I was told would eventually result in their demise, because they like N and P and without them they will starve. I also heard that they have a limited lifespan or about 2 years, so unless you frag the parent it will eventually die and can release a toxin that will take down your tank. The RSPX do not have the stench that the Waving Hand / Anthelia do, and I think those are also in the Xenia family. Boy do I know what you are talking about. Reminds me of how my hands smell after cleaning a Northern Pike. Eww. The Anthelia don't seems to be affected by the ATS, but I did start over-feeding the tank to keep the Xenia from dying en mass and wiping out the tank.
The Xenia did recede for about a month after installing the ATS, but they're back strong again. So go figure.
My tanks: 120 Reef w/L2 Algae Scrubber, 60 Reef Pond w/floating Algae Scrubber, 40 Breeder Reef w/L2 UAS Tester Algae Scrubber
I maintain: 144 SW Reef w/L2 Algae Scrubber | 200 SW Reef w/L4 Algae Scrubber
Special knowledge: Algae Scrubbers, Acrylic Fabrication