I've had no luck getting my clowns to host in either of my nems.
They've got their choice of a RBTA that had been hosting a pair of percs in its previous tank or an LTA.
I tried the clownfish clip, pictures of clowns, etc.
I even tried asking them nicely, telling them that they thought they were too good for their new houses, etc. They didn't listen to me either.
I figure just as I give up hope they'll dive in there one day.