Hey Ess,
Sometimes it can hurt the coral, but many adjust. At work I had two clowns hosting in a torch, at first I thought it was goind to kill the torch because it would rapidly close, after a week it got used to the attention and handled it fine.
At home I have two that are hosted by a large colt, it resisted at first and now it is very happy with the clowns.
One of my friends had a frogspawn that did crap out after too much attention from his maroon clown, but it then moved into a hammer and it adapted fine.
HTH