I was in the same boat as you. I had bought a picasso clown, added it to my tank which has three anemone's. Wouldn't go near any of them.
Found another picasso over the weekend all snuggled up in a bubble tip, so I bought it. Added the picasso to my tank and it went immediately to the anemone. The other picasso saw it, then proceeded to join the new clown.
I think it's kind of a monkey see monkey do type of thing.
This may sound crazy, but I've read a few different threads on the internet where people played a youtube video of clowns hosting an anemone, and it worked. I've never tried this, but it might be worth a shot.