[Reefer Addict]

If it's a tank-raised clown they tend to be more host-resistant than wild captures. I guess that it's part instinct, and part learned behaviour that determines a clown's hosting ability. Tank-raised clowns don't have exposure to anemones usually until they're put into a multi-species tank.
My tank-raised ocellaris clowns are currently hosting in my pink tree coral... though I hope they eventually take to the BTA I added a few days ago.
They started out hosting with my MagFloat scraper until it moved around on them too much.
I guess they're just a little confused...