I typically find that clowns will hang out wherever they're most comfortable in a tank when first introduced.
Example...If there is already a fish population and you put a pair in, they might end up in the top corner of the tank for weeks, months, etc. Or if you drop them down a acrylic tube directly into the anemone....they will most likely stay there because they feel secure.
I've had clowns that wouldn't touch my anemone for months and others that plunge directly into them.
Recently...I had a small clown that was absolutely terrified of a LTA. I'd try to push him into it and he would rather get hit with the PVC pipe than go into it. I put him in a cup with the nem and he stayed at the top. So I then dropped the anemone on him in about 3" of water.
He was scared but quickly realized that this was better than the originally thought. I know I know...so cruel!!
Then I couldn't get him out of it.
I honestly think that he had never been hosted by one, because he was a very young clown. Most of my others usually dive right into them fairly quick. They really seem to prefer BTA, Magnifica, and Gigantea's.