Had major outbreaks of these little buggers and tried a few methods :
Lysmata Wundermanni : never touched it. was told that ( by other fellow reefers ) that since I do feed a lot my fishes, they were more insterested in the leftovers rather than the Apistasia
Chelmon Rostratus : had a few but not a solution by any means. He only picks the small ones. The big ones he looks at me and seems to say "you have it"
Hot water & Kalkwasser seringe : that's how I got rid of them. very precise method and worked for me wonders.
Products : never tried one... dont trust on miracle products that come in a bottle. Also I always kept anemones ( Entacqmea Quadricolors ) so I was afraid that if I pour down a product in the whole tank to kill apistasia that would affect my anemones, hence never used them.
On a side note : I never saw / heard a Lysmata Seticauda that could eat apistasia.. although they are almost identical to the tropical "cousin" ( Lysmata Wurdermani ) they are not keen on apistasia, or so I've been told. They are quite often here in Portugal, since we have them on the beach ( Seticauda's... ) and most reefers collect them when the tide is low from pools... Portugal water is cold ( by reef standards ), average of 18-22c , but low tide pools can get up to 35c , so anything that can live there ( Seticauda's are trapped there often ) can be safely put in a reef tank ( doesnt mean is reef safe, means its reef temperature safe
) .
And I never heard anyone with Seticaudas saying that they ate apistasia.