try the picture method! google an image of a "similar looking" clownfish with a host anmone. print it out and slap that sucker on your tank, preferably by the desired host anemone. got my percula into frogspawn!
ON the glass. Don't actually place a printed picture in the water...
As for hosting, it is hit and miss. They may host a power head or rock, or you may get lucky had they may host your anemone.