I had a similar problem, my clownfish didn't go into the long tentacle anenome for almost a week and I got fed up with it, but i found out something that worked PERFECTLY.
I took the anenome and put it in my net for my tank. Then using the net, my hands, my girlfriends's hands, and whatever else we could find, we managed to catch the clown in the same net with the anenome, and then i kept it pressed tightly up against the glass. At first, the clownfish looked like it was getting stung and hurt, but i tried to give it a little room in the net so that it had some room where it wasn't directly touching the anenome.
I felt really bad because my clownfish looked like it was getting hurt, but I kept it in the net pressed tightly against the glass. Eventually the clownfish began swimming into the anenome on its own, and after about 15 minutes it was snuggling the anenome like crazy. I slowly took the net away from the glass, and gently popped out the anenome (with the clowfish hovering over it) and placed it into position. Since then, my clownfish doesnt' stray from it except to eat, and i've had it for about 3 months now. Enjoy and good luck!
