Most snails will consume diatoms, and that is what I truly believe that is. Korallen makes excellent products but they are pricey, and I do not believe that is cyano. If you grab some with your fingers and it feels super slimy, with air bubbles trapped underneath the "slimyness" (dont think thats a word, oh well) then it could be cyano. One thing cyano absolutely hates is high flow, position your powerhead in that direction, without the stuff or the sand blowing around, cyano will not survive the high flow for long.
I really like Astrea snails personally, as I run into dinos with nearly every tank started with dry rock these days, and they seem to be able to handle the toxicity of the dinos.