Others have stated that placing a picture of a clown in an anemone on the side of the glass has worked. Sounds silly, but worth a try.
I recently read an article that clowns react to smell to find their anemones. If this is true, I think it would explain better why some clowns will only go in their native anemones. It seems to me easier to accept the idea that some clowns accept "smell" of another anemone than to think that the whole instinct has been bred out of captive-born clowns (like some people think).
I do know this. My occelaris ignored everything in my reef tank including a BTA for over a year, but the MINUTE I put them in their own tank with their native nem (h. mag) they were all over it like stink on cheese. I found their behaviour very odd until they had their native nem with them. Then they were like whole different fish.
With that said, spare yourself the pain of getting an h. mag, lol. They are a bizzzatch to keep. S. gigantea might be a little easier, but not much.